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Drug overview for HALOPERIDOL (haloperidol):
Generic name: HALOPERIDOL (HAL-oh-PER-i-dol)
Drug class: Antipsychotics
Therapeutic class: Central Nervous System Agents
Haloperidol is a butyrophenone-derivative antipsychotic agent. The drug is considered a conventional or first-generation antipsychotic agent.
No enhanced Uses information available for this drug.
Generic name: HALOPERIDOL (HAL-oh-PER-i-dol)
Drug class: Antipsychotics
Therapeutic class: Central Nervous System Agents
Haloperidol is a butyrophenone-derivative antipsychotic agent. The drug is considered a conventional or first-generation antipsychotic agent.
No enhanced Uses information available for this drug.
DRUG IMAGES
HALOPERIDOL 10 MG TABLET
HALOPERIDOL 20 MG TABLET
HALOPERIDOL 5 MG TABLET
HALOPERIDOL 0.5 MG TABLET
HALOPERIDOL 1 MG TABLET
HALOPERIDOL 2 MG TABLET
The following indications for HALOPERIDOL (haloperidol) have been approved by the FDA:
Indications:
Gilles de la Tourette syndrome
Psychotic disorder
Schizophrenia
Professional Synonyms:
Combined vocal and motor tics for more than one year
Delusional
Dementia praecox
Gilles de la Tourette's syndrome
Parergasia
Psychosis
Psychotic disturbance
Psychotic
Tourette's disorder
Tourette's syndrome
Indications:
Gilles de la Tourette syndrome
Psychotic disorder
Schizophrenia
Professional Synonyms:
Combined vocal and motor tics for more than one year
Delusional
Dementia praecox
Gilles de la Tourette's syndrome
Parergasia
Psychosis
Psychotic disturbance
Psychotic
Tourette's disorder
Tourette's syndrome
The following dosing information is available for HALOPERIDOL (haloperidol):
Dosage of haloperidol lactate and the decanoate is expressed in terms of haloperidol.
There is considerable interindividual variation in optimum dosage requirements of haloperidol, and dosage must be carefully adjusted according to individual requirements and response, using the lowest possible effective dosage. Dosage should be increased more gradually in children and in debilitated, emaciated, or geriatric patients. Because of the risk of adverse reactions associated with cumulative effects of butyrophenones, patients with a history of long-term therapy with haloperidol and/or other antipsychotic agents should be evaluated periodically to determine whether maintenance dosage could be decreased or drug therapy discontinued.
For the symptomatic management of psychotic disorders or Tourette's disorder in adults with moderate symptomatology and in geriatric or debilitated patients, the manufacturers state that the usual initial oral dosage of haloperidol is 0.5-2 mg administered 2 or 3 times daily. To achieve prompt control, higher initial dosages may be required in some patients.
Subsequent dosage should be carefully adjusted according to the patient's tolerance and therapeutic response. Dosage during prolonged maintenance therapy should be kept at the lowest effective level.
For the symptomatic management of psychotic disorders or Tourette's disorder in adults with severe symptomatology and/or chronic or resistant disorders, the manufacturers state that the usual initial oral dosage of haloperidol is 3-5 mg administered 2 or 3 times daily. To achieve prompt control, higher initial dosages may be required in some patients. Subsequent dosage should be carefully adjusted according to the patient's tolerance and therapeutic response.
Dosage during prolonged maintenance therapy should be kept at the lowest effective level.
Similarly, the American Psychiatric Association (APA) recommends oral haloperidol dosages ranging from 5-20 mg daily in the treatment of adults with schizophrenia. The APA states that determining the optimal dosage of antipsychotic agents during the acute phase of schizophrenia is complicated because there usually is a delay between initiation of therapy and full therapeutic response. An initial response to antipsychotic therapy may take 2-4 weeks and up to 6 months or longer may be needed for a full or optimal response.
Patients who remain severely disturbed or inadequately controlled despite receiving recommended dosages of haloperidol may require dosage adjustment. Some manufacturers state that oral haloperidol dosages up to 100 mg daily may be necessary in some cases to achieve an optimal response. In addition, these manufacturers further state that haloperidol has been used infrequently in dosages exceeding 100 mg daily in severely resistant disorders in adults, but that the limited use has not demonstrated the safety of prolonged administration of such high dosages of the drug.
However, extensive clinical experience suggests that higher-dosage haloperidol regimens (i.e., those exceeding 20-40 mg daily) are unlikely to be more effective or result in a faster clinical response in the majority of patients with schizophrenia, including in those with refractory or chronic schizophrenia, and supports the use of more moderate dosage regimens (i.e., from 4 mg daily up to 15-20 mg daily) in such patients. In addition, high-dosage haloperidol regimens are more likely to be associated with unacceptable short- and long-term adverse effects (see Cautions).
The usual initial oral dosage of haloperidol in children 3-12 years of age and weighing 15-40 kg is 0.5 mg daily given in 2 or 3 divided doses. Subsequent dosage may be increased by 0.5
mg daily at 5- to 7-day intervals, depending on the patient's tolerance and therapeutic response.
For the symptomatic management of psychotic disorders in children 3-12 years of age, the usual oral dosage range is 0.05-0.15 mg/kg daily given in 2 or 3 divided doses; however, severely disturbed psychotic children may require higher dosages.
Dosage during prolonged maintenance therapy should be kept at the lowest possible effective level; once an adequate response has been achieved, dosage should be gradually reduced and subsequently adjusted according to the patient's therapeutic response and tolerance.
For the management of non-psychotic behavioral problems and for the control of Tourette's disorder in children 3-12 years of age, the usual oral dosage range is 0.05-0.075 mg/kg daily given in 2 or 3 divided doses.
Unlike psychotic disorders for which prolonged therapy is usually required, non-psychotic or hyperactive behavioral problems in children may be acute, and short-term administration of haloperidol may be adequate. A maximum effective dosage of haloperidol for the management of behavioral problems in children has not been established; however, the manufacturers state that there is little evidence that improvement in behavior is further enhanced at dosages greater than 6 mg daily.
There is considerable interindividual variation in optimum dosage requirements of haloperidol, and dosage must be carefully adjusted according to individual requirements and response, using the lowest possible effective dosage. Dosage should be increased more gradually in children and in debilitated, emaciated, or geriatric patients. Because of the risk of adverse reactions associated with cumulative effects of butyrophenones, patients with a history of long-term therapy with haloperidol and/or other antipsychotic agents should be evaluated periodically to determine whether maintenance dosage could be decreased or drug therapy discontinued.
For the symptomatic management of psychotic disorders or Tourette's disorder in adults with moderate symptomatology and in geriatric or debilitated patients, the manufacturers state that the usual initial oral dosage of haloperidol is 0.5-2 mg administered 2 or 3 times daily. To achieve prompt control, higher initial dosages may be required in some patients.
Subsequent dosage should be carefully adjusted according to the patient's tolerance and therapeutic response. Dosage during prolonged maintenance therapy should be kept at the lowest effective level.
For the symptomatic management of psychotic disorders or Tourette's disorder in adults with severe symptomatology and/or chronic or resistant disorders, the manufacturers state that the usual initial oral dosage of haloperidol is 3-5 mg administered 2 or 3 times daily. To achieve prompt control, higher initial dosages may be required in some patients. Subsequent dosage should be carefully adjusted according to the patient's tolerance and therapeutic response.
Dosage during prolonged maintenance therapy should be kept at the lowest effective level.
Similarly, the American Psychiatric Association (APA) recommends oral haloperidol dosages ranging from 5-20 mg daily in the treatment of adults with schizophrenia. The APA states that determining the optimal dosage of antipsychotic agents during the acute phase of schizophrenia is complicated because there usually is a delay between initiation of therapy and full therapeutic response. An initial response to antipsychotic therapy may take 2-4 weeks and up to 6 months or longer may be needed for a full or optimal response.
Patients who remain severely disturbed or inadequately controlled despite receiving recommended dosages of haloperidol may require dosage adjustment. Some manufacturers state that oral haloperidol dosages up to 100 mg daily may be necessary in some cases to achieve an optimal response. In addition, these manufacturers further state that haloperidol has been used infrequently in dosages exceeding 100 mg daily in severely resistant disorders in adults, but that the limited use has not demonstrated the safety of prolonged administration of such high dosages of the drug.
However, extensive clinical experience suggests that higher-dosage haloperidol regimens (i.e., those exceeding 20-40 mg daily) are unlikely to be more effective or result in a faster clinical response in the majority of patients with schizophrenia, including in those with refractory or chronic schizophrenia, and supports the use of more moderate dosage regimens (i.e., from 4 mg daily up to 15-20 mg daily) in such patients. In addition, high-dosage haloperidol regimens are more likely to be associated with unacceptable short- and long-term adverse effects (see Cautions).
The usual initial oral dosage of haloperidol in children 3-12 years of age and weighing 15-40 kg is 0.5 mg daily given in 2 or 3 divided doses. Subsequent dosage may be increased by 0.5
mg daily at 5- to 7-day intervals, depending on the patient's tolerance and therapeutic response.
For the symptomatic management of psychotic disorders in children 3-12 years of age, the usual oral dosage range is 0.05-0.15 mg/kg daily given in 2 or 3 divided doses; however, severely disturbed psychotic children may require higher dosages.
Dosage during prolonged maintenance therapy should be kept at the lowest possible effective level; once an adequate response has been achieved, dosage should be gradually reduced and subsequently adjusted according to the patient's therapeutic response and tolerance.
For the management of non-psychotic behavioral problems and for the control of Tourette's disorder in children 3-12 years of age, the usual oral dosage range is 0.05-0.075 mg/kg daily given in 2 or 3 divided doses.
Unlike psychotic disorders for which prolonged therapy is usually required, non-psychotic or hyperactive behavioral problems in children may be acute, and short-term administration of haloperidol may be adequate. A maximum effective dosage of haloperidol for the management of behavioral problems in children has not been established; however, the manufacturers state that there is little evidence that improvement in behavior is further enhanced at dosages greater than 6 mg daily.
Haloperidol is administered orally. Haloperidol lactate is administered orally or by IM injection, and haloperidol decanoate is administered by IM injection. Pending accumulation of further data to establish safety and efficacy, IM administration of haloperidol lactate or decanoate in children is not recommended by the manufacturers.
Haloperidol lactate also has been administered by IV injection+ or infusion+. Haloperidol decanoate injection should not be administered IV. Haloperidol decanoate should be administered by deep IM injection into the gluteal region using a 21-gauge needle.
The manufacturers of haloperidol decanoate state that the maximum volume of haloperidol decanoate should not exceed 3 mL per IM injection site. Haloperidol lactate and decanoate injections should be inspected visually for particulate matter and discoloration prior to administration whenever solution and container permit.
Haloperidol lactate also has been administered by IV injection+ or infusion+. Haloperidol decanoate injection should not be administered IV. Haloperidol decanoate should be administered by deep IM injection into the gluteal region using a 21-gauge needle.
The manufacturers of haloperidol decanoate state that the maximum volume of haloperidol decanoate should not exceed 3 mL per IM injection site. Haloperidol lactate and decanoate injections should be inspected visually for particulate matter and discoloration prior to administration whenever solution and container permit.
| DRUG LABEL | DOSING TYPE | DOSING INSTRUCTIONS |
|---|---|---|
| HALOPERIDOL 5 MG TABLET | Maintenance | Adults take 1 tablet (5 mg) by oral route 2 times per day |
| HALOPERIDOL 10 MG TABLET | Maintenance | Adults take 1 tablet (10 mg) by oral route 2 times per day |
| HALOPERIDOL 20 MG TABLET | Maintenance | Adults take 1 tablet (20 mg) by oral route 2 times per day |
| HALOPERIDOL 0.5 MG TABLET | Maintenance | Adults take 1 tablet (0.5 mg) by oral route 2 times per day |
| HALOPERIDOL 1 MG TABLET | Maintenance | Adults take 1 tablet (1 mg) by oral route 2 times per day |
| HALOPERIDOL 2 MG TABLET | Maintenance | Adults take 1 tablet (2 mg) by oral route 2 times per day |
| DRUG LABEL | DOSING TYPE | DOSING INSTRUCTIONS |
|---|---|---|
| HALOPERIDOL 2 MG TABLET | Maintenance | Adults take 1 tablet (2 mg) by oral route 2 times per day |
| HALOPERIDOL 1 MG TABLET | Maintenance | Adults take 1 tablet (1 mg) by oral route 2 times per day |
| HALOPERIDOL 5 MG TABLET | Maintenance | Adults take 1 tablet (5 mg) by oral route 2 times per day |
| HALOPERIDOL 10 MG TABLET | Maintenance | Adults take 1 tablet (10 mg) by oral route 2 times per day |
| HALOPERIDOL 20 MG TABLET | Maintenance | Adults take 1 tablet (20 mg) by oral route 2 times per day |
| HALOPERIDOL 0.5 MG TABLET | Maintenance | Adults take 1 tablet (0.5 mg) by oral route 2 times per day |
The following drug interaction information is available for HALOPERIDOL (haloperidol):
There are 8 contraindications.
These drug combinations generally should not be dispensed or administered to the same patient. A manufacturer label warning that indicates the contraindication warrants inclusion of a drug combination in this category, regardless of clinical evidence or lack of clinical evidence to support the contraindication.
| Drug Interaction | Drug Names |
|---|---|
| Pimozide/QT Prolonging Agents SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient. MECHANISM OF ACTION: Pimozide has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of pimozide with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(3) Concurrent use of more than one drug know to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction.(3) PATIENT MANAGEMENT: The manufacturer of pimozide states under contraindications that the use of pimozide is contraindicated in patients taking other drugs which prolong the QT interval.(1) If concurrent therapy is deemed medically necessary, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(2) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
PIMOZIDE |
| Droperidol/QT Prolonging Agents SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient. MECHANISM OF ACTION: Droperidol has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of droperidol with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: Congestive heart failure, bradycardia, use of a diuretic, cardiac hypertrophy, hypokalemia, hypomagnesemia, age over 65 years, alcohol abuse, and the use of agents such as benzodiazepines, volatile anesthetics, and intravenous opiate may predispose patients to the development of prolonged QT syndrome.(1) Risk may also be increased in patients with other cardiovascular diseases (e.g. myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypocalcemia, or female gender.(3) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(3) PATIENT MANAGEMENT: The manufacturer of droperidol states under precautions drug interactions that drugs known to have the potential to prolong the QT interval should not be used together with droperidol.(1) DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(2) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
DROPERIDOL |
| Iomeprol/Neuroleptics SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient. MECHANISM OF ACTION: Neuroleptics may lower seizure threshold.(1) CLINICAL EFFECTS: Use of iomeprol in a patient receiving a neuroleptic may increase the risk of seizure.(1) PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: The manufacturer of iomeprol states that neuroleptics should be discontinued 48 hours before iomeprol use. Treatment with a neuroleptic should not be resumed until 24 hours post-procedure.(1) DISCUSSION: Because neuroleptics may lower seizure threshold, neuroleptics should be discontinued 48 hours before iomeprol use. Treatment with a neuroleptic should not be resumed until 24 hours post-procedure.(1) |
IOMERON 350 |
| Disopyramide/QT Prolonging Agents SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient. MECHANISM OF ACTION: Concurrent use of disopyramide and agents known to prolong the QT interval may result in additive or synergistic effects on the QTc interval.(1) CLINICAL EFFECTS: Concurrent administration may result in prolongation of the QTc interval and life-threatening cardiac arrhythmias, including torsades de pointes. PREDISPOSING FACTORS: The risk of torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(3) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or and/or renal/hepatic dysfunction).(3) PATIENT MANAGEMENT: The Australian manufacturer of disopyramide states that concurrent use with agents liable to produce torsades de pointes, including tricyclic or tetracyclic antidepressants, erythromycin, vincamine, and sultopride, is contraindicated.(1) If alternatives are not available and concurrent therapy is deemed medically necessary, obtain serum calcium, magnesium, and potassium levels and monitor ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(2) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
DISOPYRAMIDE PHOSPHATE, NORPACE, NORPACE CR |
| Artemether-Lumefantrine/QT Prolonging Agents SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient. MECHANISM OF ACTION: Concurrent use of artemether-lumefantrine and agents known to prolong the QT interval may result in additive or synergistic effects on the QTc interval.(1) CLINICAL EFFECTS: Concurrent administration may result in prolongation of the QTc interval and life-threatening cardiac arrhythmias, including torsades de pointes. PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(4) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, and/or renal/hepatic dysfunction).(4) PATIENT MANAGEMENT: The UK manufacturer of artemether-lumefantrine states that the use of artemether-lumefantrine in patients taking drugs that are known to prolong the QTc interval is contraindicated. These agents include class IA and III antiarrhythmics; neuroleptics; antidepressive agents; some macrolides, fluoroquinolones, imidazole and triazole antifungals; terfenadine; astemizole; and cisapride.(1) The US manufacturer of artemether-lumefantrine states that the use of artemether-lumefantrine should be avoided in patients taking drugs that are known to prolong the QTc interval. These agents include class IA and III antiarrhythmics; neuroleptics; antidepressive agents; some macrolides, fluoroquinolones, imidazole and triazole antifungals; terfenadine; astemizole; and cisapride.(2) If concurrent therapy is deemed medically necessary, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(3) |
COARTEM |
| Dronedarone/QT Prolonging Agents SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient. MECHANISM OF ACTION: Concurrent use of dronedarone and agents known to prolong the QT interval may result in additive or synergistic effects on the QTc interval.(1) CLINICAL EFFECTS: Concurrent administration may result in prolongation of the QTc interval and life-threatening cardiac arrhythmias, including torsades de pointes. PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(3) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, and/or renal/hepatic dysfunction).(3) PATIENT MANAGEMENT: The US manufacturer of dronedarone states that the use of drugs or herbal products that are known to prolong the QTc interval is contraindicated. These agents include phenothiazine anti-psychotics, tricyclic antidepressants, certain oral macrolide antibiotics, and Class IA and III antiarrhythmics.(1) If concurrent therapy is deemed medically necessary, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(2) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
MULTAQ |
| Anagrelide/QT Prolonging Agents SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient. MECHANISM OF ACTION: Concurrent use of anagrelide with agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of anagrelide with agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: The US manufacturer of anagrelide states that anagrelide should not be used in patients taking medications known to prolong the QT interval.(1) If concurrent therapy is deemed medically necessary, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: In a thorough QT study, dose-related QT changes were observed with anagrelide. The maximum mean change in QTcI (95% CI) in comparison to placebo was 7.0 (9.8) ms and 13.0 (15.7) msec following doses of 0.5 mg and 2.5mg, respectively.(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(3) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
AGRYLIN, ANAGRELIDE HCL |
| Levoketoconazole/QT Prolonging Agents SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient. MECHANISM OF ACTION: Levoketoconazole has been observed to prolong the QTc interval in a dose-dependent manner. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of levoketoconazole with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: The US manufacturer of levoketoconazole states that levoketoconazole is contraindicated with other agents that prolong the QT interval.(1) Levoketoconazole is also contraindicated in patients with a prolonged QTcF interval of greater than 470 msec at baseline, history of torsades de pointes, ventricular tachycardia, ventricular fibrillation, or long QT syndrome (including first-degree family history). Use caution in patients with other risk factors for QT prolongation including congestive heart failure, bradyarrhythmias, and uncorrected electrolyte abnormalities. Consider more frequent ECG monitoring. Prior to starting levoketoconazole, obtain a baseline ECG and correct hypokalemia or hypomagnesemia. If a patient develops QT prolongation with a QTc interval greater than 500 msec, temporarily discontinue levoketoconazole. After resolution of prolonged QTc interval, levoketoconazole may be resumed at a lower dose. If QTc interval prolongation recurs, permanently discontinue levoketoconazole.(1) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: During phase 1 and 2 studies, which excluded patients with baseline QTcF interval greater than 470 msec, 4 (2.4%) patients experienced QTcF > 500 msec, and 23 (14.7%) patients experienced change-from-baseline QTcF > 60 msec.(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(3) |
RECORLEV |
There are 70 severe interactions.
These drug interactions can produce serious consequences in most patients. Actions required for severe interactions include, but are not limited to, discontinuing one or both agents, adjusting dosage, altering administration scheduling, and providing additional patient monitoring. Review the full interaction monograph for more information.
| Drug Interaction | Drug Names |
|---|---|
| Cabergoline/Selected Dopamine Blockers SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Dopamine (D2) blockers such as the phenothiazines, butyrophenones, thioxanthenes and atypical antipsychotics may decrease the effects of cabergoline, a dopamine agonist.(1) CLINICAL EFFECTS: Concurrent administration of cabergoline with dopamine blockers (e.g. phenothiazines, butyrophenones, or thio xanthines) may decrease the effectiveness of cabergoline.(1) Cabergoline may decrease the effectiveness of antipsychotic treatment. PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: The manufacturer of cabergoline states cabergoline(1) should not be administered concurrently with dopamine antagonists. Avoid concurrent use when possible. If cabergoline is started in a patient receiving long term antipsychotic treatment, monitor closely for loss of antipsychotic efficacy. If an antipsychotic is required for a patient on long term cabergoline therapy, consider use of a shorter half-life, less potent dopamine (D2) blocking atypical antipsychotic (e.g. clozapine, quetiapine) and monitor closely. DISCUSSION: The manufacturer of cabergoline state that it should not be administered concurrently with dopamine antagonists. |
CABERGOLINE |
| Thioridazine/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Thioridazine has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of thioridazine with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: Use of thioridazine in patients with reduced CYP2D6 activity (either through genetic predisposition or use of drugs that inhibit CYP2D6 activity) may increase the risk of torsades de pointes and/or sudden death in patients taking thioridazine.(1) The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(4) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. impairment in the drug metabolism or elimination, and/or renal/hepatic dysfunction).(4) PATIENT MANAGEMENT: The manufacturer of thioridazine states under contraindications that the use of thioridazine should be avoided in combination with other drugs that are known to prolong the QTc interval. If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(2) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
THIORIDAZINE HCL, THIORIDAZINE HYDROCHLORIDE |
| Amiodarone/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Amiodarone has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1-3) CLINICAL EFFECTS: The concurrent use of amiodarone with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1-3) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(6) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(6) PATIENT MANAGEMENT: The US manufacturer of amiodarone states that the concurrent use of QT prolonging agents should be avoided and that the need to co-administer amiodarone with any other drug known to prolong the QTc interval must be based on a careful assessment of the potential risks and benefits of doing so for each patient.(3) The Australian(1) and UK(2) manufacturers of amiodarone states that concurrent use of agents known to cause torsades de pointes is contraindicated. DISCUSSION: QTc prolongation has been reported during concurrent amiodarone and azole antifungals, fluoroquinolones, and macrolide antibiotics.(3) A retrospective review of patients who received concurrent amiodarone and haloperidol over a 24 month period found 49 patients who received concurrent therapy for 381 exposures. The mean increase in QTc interval was 9.8 msec; the average change in QTc interval per patient was 23.6 msec.(4) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(5) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
AMIODARONE HCL, AMIODARONE HCL-D5W, NEXTERONE, PACERONE |
| Ziprasidone/Selected QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Ziprasidone has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of ziprasidone with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(1,3) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(3) PATIENT MANAGEMENT: The manufacturer of ziprasidone states under contraindications that ziprasidone should not be used with other drugs that prolong the QT interval such as dofetilide, sotalol, quinidine, other Class Ia and III anti-arrhythmics, mesoridazine, thioridazine, chlorpromazine, droperidol, pimozide, sparfloxacin, gatifloxacin, moxifloxacin, halofantrine, mefloquine, pentamidine, arsenic trioxide, levomethadyl acetate, dolasetron mesylate, probucol or tacrolimus.(1) It would be prudent to avoid the use of ziprasidone with medicines suspected of prolonging the QT interval. If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(2) |
GEODON, ZIPRASIDONE HCL, ZIPRASIDONE MESYLATE |
| Ivabradine/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: QT prolongation may be exacerbated by ivabradine-induced reduction in heart rate.(1) CLINICAL EFFECTS: Concurrent use of ivabradine and agents known to prolong the QT interval may exacerbate QT prolongation.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(3) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(3) PATIENT MANAGEMENT: The UK, AU, and Canadian manufacturer of ivabradine states that concurrent use with cardiovascular and non-cardiovascular QT prolonging agents should be avoided.(1,4,5) The Canadian manufacturer states that if concurrent therapy is deemed necessary, close cardiac monitoring (12-lead ECG) is required. Depending on the ECG results, ivabradine dosing may need to be decreased or stopped.(4) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(2) |
CORLANOR, IVABRADINE HCL |
| Paliperidone/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Paliperidone has been shown to cause a modest increase in the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1,2) CLINICAL EFFECTS: The concurrent use of paliperidone with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1,2) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(4) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(4) PATIENT MANAGEMENT: The US manufacturer of paliperidone states that the use of paliperidone should be avoided with other drugs that are known to prolong the QTc interval, including Class IA and Class III antiarrhythmics, antipsychotics, antibiotics such as gatifloxacin and moxifloxacin, or any other class of medications known to prolong the QTc interval.(1,2) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(3) |
ERZOFRI, INVEGA, INVEGA HAFYERA, INVEGA SUSTENNA, INVEGA TRINZA, PALIPERIDONE ER |
| Nilotinib/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Nilotinib prolongs the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1,3) CLINICAL EFFECTS: The concurrent use of nilotinib with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1,3) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(4) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(4) PATIENT MANAGEMENT: The US manufacturer of nilotinib states that the use of nilotinib should be avoided with other drugs that are known to prolong the QTc interval. Should treatment with a QT prolonging agent be required, interruption of nilotinib therapy should be considered. If concurrent therapy cannot be avoided, monitor patients closely for prolongation of the QT interval and follow recommended nilotinib dosage adjustments for QT prolongation.(1) Consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. The UK manufacturer of nilotinib states that the use of nilotinib should be used with caution with other drugs that are known to prolong the QTc interval.(3) DISCUSSION: A retrospective review of 618 cancer patients treated with 902 administrations of tyrosine kinase inhibitors were evaluated for rate and incidence of QTc prolongation. In patients who received nilotinib, QTc prolongation was identified in 29 (38.7%) with 1 (3.5%) having Grade 1 (QTc 450-480 ms) and 2 (7%) having Grade 2 (QTc 480-500 ms). Grade 3 events occurred in 9 (31%) having QTc greater than or equal to 500 ms and 17 (58.6%) having QTc change greater than or equal to 60 ms. No patients developed ventricular tachycardia, sudden cardiac death, or TdP.(5) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(2) |
DANZITEN, NILOTINIB HCL, TASIGNA |
| Toremifene/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Toremifene has been shown to prolong the QTc interval in a dose-related and concentration-related manner.(1) Concurrent use of toremifene and agents known to prolong the QT interval may result in additive or synergistic effects on the QTc interval.(1,2) CLINICAL EFFECTS: Concurrent administration may result in prolongation of the QTc interval and life-threatening cardiac arrhythmias, including torsades de pointes.(1,2) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(4) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, and/or renal/hepatic dysfunction).(4) PATIENT MANAGEMENT: The US manufacturer of toremifene states that concurrent use should be avoided. If treatment with an agent known to prolong the QT interval is required, toremifene therapy should be interrupted. If it is not possible to interrupt toremifene therapy, patients should be closely monitored. Electrocardiograms (ECGs) should be obtained.(1) Consider obtaining serum calcium, magnesium, and potassium levels and correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. The UK manufacturer of toremifene states that the use of other drugs that are known to prolong the QTc interval is contraindicated. These agents include class IA and III antiarrhythmics, astemizole, bepridil, cisapride, diphemanil, erythromycin IV, halofantrine, haloperidol, mizolastine, moxifloxacin, pentamidine, phenothiazines, pimozide, sertindole, terfenadine, and vincamine IV.(2) DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(3) |
FARESTON, TOREMIFENE CITRATE |
| Lopinavir/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Lopinavir has been shown to prolong the QTc interval by 5 msec. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of lopinavir with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(3) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, and/or renal/hepatic dysfunction).(3) PATIENT MANAGEMENT: The US manufacturer of lopinavir states that the concurrent administration of other drugs that are known to prolong the QTc interval should be avoided.(1) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: In a randomized, placebo and active controlled crossover study in 39 healthy subjects designed to evaluated QTc intervals, lopinavir/ritonavir increased QTc by 5.3 msec and 15.2 msec for 400/100 mg twice daily and 800/200 mg twice daily, respectively.(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(2) |
KALETRA, LOPINAVIR-RITONAVIR |
| Iloperidone/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Iloperidone has been shown to prolong the QTc interval by 9 msec at dosages of 12 mg twice daily. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of iloperidone with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, congenital prolongation of the QT interval, female gender, advanced age and with concurrent use of inhibitors of CYP3A4 or CYP2D6, which metabolize iloperidone. Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(3) PATIENT MANAGEMENT: The US manufacturer of iloperidone states that the concurrent administration of other drugs that are known to prolong the QTc interval should be avoided. Disopyramide and procainamide should not be used to treat iloperidone-overdose-induced arrhythmias.(1) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(2) Coadministration of ketoconazole (200 mg twice daily, an inhibitor of CYP3A4) and iloperidone (12 mg twice daily) was associated with a mean QTcF increase of 19 msec from baseline, compared with an increase of 9 msec with iloperidone alone.(1) Coadministration of paroxetine (20 mg daily, an inhibitor of CYP2D6) and iloperidone (12 mg twice daily) was associated with a mean QTcF increase of 19 msec from baseline, compared with an increase of 9 msec with iloperidone alone.(1) |
FANAPT |
| Quinine/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Quinine has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of quinine with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(3) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, and/or renal/hepatic dysfunction).(3) PATIENT MANAGEMENT: The US manufacturer of quinine states that concurrent use with agents known to prolong the QT interval should be avoided.(1) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports. |
QUALAQUIN, QUININE HCL, QUININE SULFATE |
| Propafenone/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Propafenone has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of propafenone with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(3) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, and/or renal/hepatic dysfunction).(3) PATIENT MANAGEMENT: The manufacturer of propafenone states that the use of propafenone with other agents known to prolong the QT interval should be avoided.(1) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(2) |
PROPAFENONE HCL, PROPAFENONE HCL ER |
| Moxifloxacin/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Moxifloxacin has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of moxifloxacin with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(3) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(3) PATIENT MANAGEMENT: The manufacturer of moxifloxacin states that moxifloxacin should avoided in patients receiving agents known to prolong the QT interval.(1) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTC interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(2) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
AVELOX IV, MOXIFLOXACIN, MOXIFLOXACIN HCL |
| Vandetanib/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Vandetanib has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of vandetanib with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(3) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(3) PATIENT MANAGEMENT: The manufacturer of vandetanib states that the use of vandetanib with other agents known to prolong the QT interval should be avoided.(1) The manufacturer of vandetanib states therapy should be interrupted if Corrected QT interval, Frederica (QTcF) is greater than 500 ms; resume at a reduced dose when the QTcF returns to less than 450 ms. Consult current prescribing information for further details.(1) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Vandetanib has been shown to prolong the QTc interval in a dose-dependent manner. Vandetanib has a long half-life (19 days) and effects on the QTc interval may not resolve quickly following vandetanib discontinuation.(1) A retrospective review of 618 cancer patients treated with 902 administrations of tyrosine kinase inhibitors were evaluated for rate and incidence of QTc prolongation. In patients who received vandetanib, QTc prolongation was identified in 4 (80%) with 0 (0%) having Grade 1 (QTc 450-480 ms) and 1 (25%) having Grade 2 (QTc 480-500 ms). Grade 3 events occurred in 1 (25%) having QTc greater than or equal to 500 ms and 2 (50%) having QTc change greater than or equal to 60 ms. No patients had ventricular tachycardia, sudden cardiac death, or TdP.(4) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(2) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
CAPRELSA |
| Metoclopramide/Antipsychotics; Phenothiazines; Rivastigmine SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: These agents block dopamine (D2) receptors. D2 blockade can cause extrapyramidal reactions, such acute dystonic reactions, pseudoparkinsonian tremors, akathisia, or tardive dyskinesia. Neuroleptic malignant syndrome may also occur in patients receiving D2 blockers. The risk of these adverse effects may be increased by concurrent use.(1-3) CLINICAL EFFECTS: Concurrent use may increase the risk of extrapyramidal reactions (e.g. acute dystonic reactions, pseudoparkinsonian tremors, akathisia, or tardive dyskinesia) and neuroleptic malignant syndrome. Tardive dyskinesia, which may be permanent, typically affects the facial muscles and may result in uncontrollable lip smacking, chewing, puckering of the mouth, frowning or scowling, sticking out the tongue, blinking and moving the eyes, and shaking of the arms and/or legs.(1-3) Symptoms of neuroleptic malignant syndrome include hyperpyrexia, muscle rigidity, altered mental status, an autonomic instability (irregular pulse or blood pressure, tachycardia, diaphoresis, and cardiac arrhythmias), elevated creatine phosphokinase, myoglobinuria (rhabdomyolysis), and acute renal failure.(1) PREDISPOSING FACTORS: Patients with Parkinson's or Lewy Body Disease may be more likely to have extrapyramidal reactions or unmasking of their primary disease symptoms. The risk of extrapyramidal symptoms is also increased in patients on metoclopramide for longer than 12 weeks. Elderly patients, especially elderly women, and diabetics are at higher risk of developing tardive dyskinesia. Other extrapyramidal symptoms, like acute dystonia, have occurred more frequently in patients younger than 30 years old.(1) PATIENT MANAGEMENT: The concurrent use of metoclopramide and agents likely to cause extrapyramidal reactions should be avoided.(1) If concurrent use is warranted, monitor patients closely for extrapyramidal reactions and neuroleptic malignant syndrome. The manufacturer of metoclopramide says to avoid treatment with metoclopramide for longer than 12 weeks, and to use the lowest possible dose.(1) Discontinue therapy if symptoms occur. Instruct patients to seek immediate medical attention if symptoms develop. Symptoms of extrapyramidal reactions, including tardive dyskinesia, include involuntary movements of limbs and facial grimacing, torticollis, oculogyric crisis, rhythmic protrusion of the tongue, bulbar type of speech, trismus, and/or dystonic reactions resembling tetanus/stridor/dyspnea.(3) DISCUSSION: Both metoclopramide and phenothiazines can cause extrapyramidal reactions, such as tardive dyskinesia, and neuroleptic malignant syndrome. The risk may be increased by concurrent use.(1,2) Extrapyramidal symptoms have been reported with concurrent metoclopramide and neuroleptics, prochlorperazine, and chlorpromazine.(4-6) |
GIMOTI, METOCLOPRAMIDE HCL, REGLAN |
| Dofetilide/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Dofetilide has been shown to prolong the QTc interval in a dose-dependent fashion. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of dofetilide with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes(TdP).(1) Agents linked to this monograph are: chloroquine, chlorpromazine, dolasetron, domperidone, haloperidol, pentamidine, probucol, and propoxyphene. PREDISPOSING FACTORS: Renal impairment may increase risk for excessive QTc prolongation as dofetilide is primarily renally eliminated. To prevent increased serum levels and risk for ventricular arrhythmias, dofetilide must be dose adjusted for creatinine clearance < or = to 60 mL/min.(1) Risk factors for QT prolongation include: cardiovascular disease (e.g. heart failure, recent myocardial infarction, history of torsades de pointes, congenital long QT syndrome), female sex, hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, advanced age, and concurrent use of agents known to cause QT prolongation.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: The manufacturer of dofetilide states that the use of dofetilide with other agents known to prolong the QTc interval is not recommended.(1) Use available alternative agents whenever possible. If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. If dofetilide dose is increased or if dofetilide therapy is reinitiated after an interruption, the patient should be hospitalized for continuous ECG monitoring.(1) DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(3) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
DOFETILIDE, TIKOSYN |
| Trazodone (Greater Than or Equal To 100 mg)/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Concurrent use of trazodone with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1,2) CLINICAL EFFECTS: The use of trazodone in patients maintained on agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1,2) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: The US manufacturer of trazodone states that concurrent use with agents known to prolong the QT interval should be avoided.(1) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Trazodone has been reported to prolong the QT interval.(1) A thorough QT study in 20 subjects evaluated the effects of trazodone at doses of 20 mg, 60 mg and 140 mg. There was no evidence of QTc prolongation at the lowest trazodone dose of 20mg (mean effect on QTc of 4.5 ms 95% CI 3.7-5.3 ms), but at 60 mg and 140 mg, there was a significant effect that exceeds the E14 FDA Guidelines threshold of prolonging the QT/QTc interval by more than 5 ms. The study found a dose-dependent effect on QTc prolongation starting at 60 mg with a mean effect on QTc of 12.3 ms (95% CI 11-13.6 ms) and increasing with a 140 mg dose to a mean effect on QTc of 19.8 ms (95% CI 17.6-22.1).(3) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(4) |
RALDESY, TRAZODONE HCL |
| Citalopram/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1-3) CLINICAL EFFECTS: The use of citalopram in patients maintained on agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1-3) PREDISPOSING FACTORS: Higher doses of citalopram, especially doses greater than 40 mg, may increase the risk of QT prolongation. The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(4) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(4) PATIENT MANAGEMENT: Concurrent use of citalopram with agents known to prolong the QT interval should be avoided. Due to the risk of QT prolongation, citalopram doses greater than 40 mg once daily are not recommended. Citalopram doses should be limited to 20 mg once daily in patients who are CYP2C19 poor metabolizers or patients receiving CYP2C19 inhibitors. If patients have a persistent QTc measurement > 500 ms, discontinue citalopram. If a patient develops symptoms including dizziness, palpitations, or syncope, further evaluation is warranted included cardiac monitoring. The manufacturer recommends ECG monitoring in patients for whom citalopram is not recommended, including those receiving concurrent therapy with agents known to prolong the QT interval. Citalopram should be discontinued in patients with persistent QTc measurements greater than 500 ms.(1-2) Consider obtaining serum calcium, magnesium, and potassium levels at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Citalopram has been associated with dose-depended increases in the QTc interval. In healthy subjects, the maximum mean difference in QTc interval seen with 20 mg of citalopram and 60 mg of citalopram were 8.5 msec (90% CI = 6.2-10.8 msec) and 18.5 msec (90% CI = 16.0-21.0 msec), respectively. Based on extrapolation, a 40 mg dose of citalopram is expected to produce a mean increase in the QTc interval of 12.6 msec (90% CI = 10.9-14.3 msec).(1) In a clinical trial of use of citalopram for agitation in Alzheimer's disease, citalopram (30 mg daily) was associated with a mean increase in QTc of 18.1 msec.(5) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(6) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
CELEXA, CITALOPRAM HBR |
| Flecainide/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Flecainide has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of flecainide with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes(TdP).(1) PREDISPOSING FACTORS: In general, the risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(1) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(1) PATIENT MANAGEMENT: If possible, avoid the use of flecainide with other agents known to prolong the QT interval. If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(2) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
FLECAINIDE ACETATE |
| Hydroquinidine; Quinidine/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Hydroquinidine and quinidine have been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of hydroquinidine or quinidine with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes(TdP).(1) PREDISPOSING FACTORS: In general, the risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(1) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(1) PATIENT MANAGEMENT: If possible, avoid the use of hydroquinidine or quinidine with other agents known to prolong the QT interval. If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(2) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
NUEDEXTA, QUINIDINE GLUCONATE, QUINIDINE SULFATE |
| Ibutilide/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Ibutilide has been shown to prolong the QTc interval.(1) Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(2) CLINICAL EFFECTS: The concurrent use of ibutilide with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes(TdP).(1,2) PREDISPOSING FACTORS: In general, the risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: If possible, avoid the use of ibutilide with other agents known to prolong the QT interval.(1) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: In a study in healthy volunteers, intravenous infusions of ibutilide resulted in prolongation of the QT interval that was directly correlated with ibutilide plasma concentration during and after 10-minute and 8-hour infusions.(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(3) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
CORVERT, IBUTILIDE FUMARATE |
| Procainamide/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Procainamide has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of procainamide with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes(TdP).(1) PREDISPOSING FACTORS: In general, the risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(1) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(1) PATIENT MANAGEMENT: If possible, avoid the use of procainamide with other agents known to prolong the QT interval. If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(2) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
PROCAINAMIDE HCL |
| Sotalol/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Sotalol has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of sotalol with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation may be increased by reduced creatinine clearance, female gender, larger doses of sotalol, and a history of cardiomegaly or congestive heart failure.(1) Risk may also be increased in patients with cardiovascular disease (e.g. myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, or advanced age.(3) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(3) PATIENT MANAGEMENT: The manufacturer of sotalol states that concurrent use with other agents known to prolong the QT interval is not recommended.(1) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(2) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
BETAPACE, BETAPACE AF, SOTALOL, SOTALOL AF, SOTALOL HCL, SOTYLIZE |
| Azithromycin/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Azithromycin has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1,2) CLINICAL EFFECTS: The concurrent use of azithromycin with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes(TdP).(1,2) PREDISPOSING FACTORS: In general, the risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: If possible, avoid the use of azithromycin with other agents known to prolong the QT interval. If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: In a randomized, placebo-controlled parallel trial 116 healthy subjects received either chloroquine (1000 mg) alone or in combination with oral azithromycin (500 mg, 1000 mg, and 1500 mg once daily). Co-administration of azithromycin increased the QTc interval in a dose- and concentration- dependent manner. In comparison to chloroquine alone, the maximum mean (95% upper confidence bound) increases in QTcF were 5 (10) ms, 7 (12) ms and 9 (14) ms with the co-administration of 500 mg, 1000 mg and 1500 mg azithromycin, respectively.(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(3) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
AZITHROMYCIN, ZITHROMAX, ZITHROMAX TRI-PAK |
| Chloroquine/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Chloroquine has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of chloroquine with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes(TdP).(1) PREDISPOSING FACTORS: In general, the risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(1) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(1) PATIENT MANAGEMENT: If possible, avoid the use of chloroquine with other agents known to prolong the QT interval. If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(2) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
CHLOROQUINE PHOSPHATE |
| Chlorpromazine/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Chlorpromazine has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of chlorpromazine with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes(TdP).(1) PREDISPOSING FACTORS: In general, the risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(1) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(1) PATIENT MANAGEMENT: If possible, avoid the use of chlorpromazine with other agents known to prolong the QT interval. If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(2) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
CHLORPROMAZINE HCL |
| Cilostazol/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Cilostazol has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of cilostazol with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes(TdP).(1) PREDISPOSING FACTORS: In general, the risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(1) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(1) PATIENT MANAGEMENT: If possible, avoid the use of cilostazol with other agents known to prolong the QT interval. If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(2) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
CILOSTAZOL |
| Donepezil/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Donepezil has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of donepezil with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes(TdP).(1) PREDISPOSING FACTORS: In general, the risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(1) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(1) PATIENT MANAGEMENT: If possible, avoid the use of donepezil with other agents known to prolong the QT interval. If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: A pharmacovigilance study based on the FDA Adverse Event Reporting System (FAERS) database found that, of a total of 33,626 cases of TdP/QT prolongation reported between January 2004 and September 2022, 430 cases occurred in patients on donepezil. The disproportionality analysis found a ROR = 8.98, 95% CI (8.16, 9.89) and a PRR = 8.88, chi-square = 2944.95.(2) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(3) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
ADLARITY, ARICEPT, DONEPEZIL HCL, DONEPEZIL HCL ODT, MEMANTINE HCL-DONEPEZIL HCL ER, NAMZARIC |
| Erythromycin/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Erythromycin has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of erythromycin with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes(TdP).(1) PREDISPOSING FACTORS: In general, the risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(1) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(1) PATIENT MANAGEMENT: If possible, avoid the use of erythromycin with other agents known to prolong the QT interval. The Australian manufacturer of erythromycin states that concurrent use with agents known to prolong the QT interval is contraindicated.(4) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(2) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
E.E.S. 200, E.E.S. 400, ERY-TAB, ERYPED 200, ERYPED 400, ERYTHROCIN LACTOBIONATE, ERYTHROCIN STEARATE, ERYTHROMYCIN, ERYTHROMYCIN ESTOLATE, ERYTHROMYCIN ETHYLSUCCINATE, ERYTHROMYCIN LACTOBIONATE |
| Fluconazole/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Fluconazole has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of fluconazole with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes(TdP).(1) PREDISPOSING FACTORS: In general, the risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(1) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(1) PATIENT MANAGEMENT: If possible, avoid the use of fluconazole with other agents known to prolong the QT interval. If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(2) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
DIFLUCAN, FLUCONAZOLE, FLUCONAZOLE-NACL |
| Pentamidine/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Pentamidine has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of pentamidine with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes(TdP).(1) PREDISPOSING FACTORS: In general, the risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(1) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(1) PATIENT MANAGEMENT: If possible, avoid the use of pentamidine with other agents known to prolong the QT interval. If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(2) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
PENTAM 300, PENTAMIDINE ISETHIONATE |
| Propofol/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Propofol has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of propofol with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes(TdP).(1) PREDISPOSING FACTORS: In general, the risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(1) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(1) PATIENT MANAGEMENT: If possible, avoid the use of propofol with other agents known to prolong the QT interval. If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(2) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
DIPRIVAN, PROPOFOL |
| Osimertinib/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Osimertinib prolongs the QTc interval.(1) Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(2,3) CLINICAL EFFECTS: The concurrent use of osimertinib with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(2,3) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(3) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(3) PATIENT MANAGEMENT: Osimertinib prolongs the QT interval. Premarket clinical trials excluded patients with a baseline QTc > or = 470 msec. In these trials 11 patients (2.7%) had increase in QTc greater than 60 msec.(1) Manufacturer recommendations: when feasible, avoid concurrent administrations of osimertinib with drugs known to prolong the QTc interval. Conduct baseline and periodic monitoring with ECGs in patients with congenital long QTc syndrome, congestive heart failure, electrolyte abnormalities (e.g. serum calcium, magnesium, and potassium), or those taking medications known to prolong the QT interval.(1) Dose adjustments (1): - If QTc is greater than 500 msec on at least 2 separate ECGs, withhold osimertinib until QTc is < 481 msec or recovery to baseline (if baseline QTc was greater than or equal to 481 msec), then resume osimertinib at 40 mg per day. - For QTc prolongation with signs or symptoms of life threatening arrhythmia, permanently discontinue osimertinib. During concomitant therapy with another QT prolonging agent, monitor patients closely for prolongation of the QT interval.(1) Obtain serum calcium, magnesium, and potassium levels and monitoring ECG at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: A retrospective review of 618 cancer patients treated with 902 administrations of tyrosine kinase inhibitors were evaluated for rate and incidence of QTc prolongation. In patients who received osimertinib, QTc prolongation was identified in 4 (25%) with 1 (25%) having Grade 1 (QTc 450-480 ms) and 1 (25%) having Grade 2 (QTc 480-500 ms). Grade 3 events occurred in 1 (25%) having QTc greater than or equal to 500 ms and 1 (25%) having QTc change greater than or equal to 60 ms. No patients had ventricular tachycardia, sudden cardiac death, or TdP.(4) In clinical studies of 1813 patients treated with osimertinib monotherapy, 1.1% of patients were found to have a QTc interval greater than 500 ms and 4.3% of patients had an increase from baseline QTc > 60 ms.(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(2) |
TAGRISSO |
| Arsenic/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Arsenic has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of arsenic with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of torsade de pointes is related to the extent of QT prolongation, concomitant administration of QT prolonging drugs, a history of torsade de pointes, preexisting QT interval prolongation, congestive heart failure, use of potassium-wasting diuretics, or other conditions that result in hypokalemia or hypomagnesemia.(1) Risk may also be increased in patients with other cardiovascular disease (e.g. myocardial infarction, congenital long QT syndrome), hypocalcemia, bradycardia, female gender, or advanced age.(2) Higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: The manufacturer of arsenic trioxide states that, if possible, drugs that are known to prolong the QT interval should be discontinued prior to therapy and caution is advised during coadministration.(1) In patients who reach a QTc interval value > 450 msec in men or >460 msec in women, withhold arsenic and any other QT prolonging agents. Monitor electrolytes and correct abnormalities. After the QTc normalizes, follow manufacturer instructions concerning restarting arsenic and escalation of dosing.(1) Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(3) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
ARSENIC TRIOXIDE, TRISENOX |
| Bedaquiline/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Concurrent use of bedaquiline with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The use of bedaquiline patients maintained on agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: Bedaquiline should be used with caution in patients receiving therapy with agents that prolong the QT interval. Patients should receive a baseline electrocardiogram (ECG) before initiation, 2 weeks after initiation, during treatment as clinically indicated, and at the expected time of maximum increase of the QT interval when receiving concurrent agents that prolong the QT interval. Bedaquiline and other QT prolonging agents should be discontinued if the patient develops a clinically significant ventricular arrhythmia or a QTcF of greater than 500 msec confirmed by repeat ECGs. If a patient develops syncope, perform an ECG.(1) Also consider obtaining serum calcium, magnesium, and potassium levels at baseline and regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: In a clinical trial, mean increases in QTc were greater in patients treated with bedaquiline than with placebo. At Week 1, bedaquiline increased QTc by an average of 9.9 msec, compared with 2.5 msec for placebo. At Week 24, bedaquiline increased QTc by an average of 15.7 msec, compared with 6.2 msec for placebo. In another clinical trial in which patients received bedaquiline with other QT prolonging agents, QT prolongation was additive and proportional to the number of QT prolonging drugs used. Patients receiving bedaquiline alone averaged a QTc increase of 23.7 msec over baseline, while patients receiving bedaquiline with at least one other QT prolonging agent averaged a QTc increase of 30.7 msec.(1) In a study, bedaquiline was coadministered with QTc prolonging agents clofazimine and levofloxacin. In the study, 5% of patients had a QTc >= 500 ms and 43% of patients had an increase in QTc >= 60 ms from baseline.(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(3) |
SIRTURO |
| Ceritinib/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The use of ceritinib in patients maintained on agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(2) Patients with severe hepatic impairment (Child-Pugh C) may be at increased risk of this interaction. Ceritinib dose reduction may be warranted in severe hepatic impairment. See prescribing information for recommendations.(1) PATIENT MANAGEMENT: When possible, avoid coadministration of ceritinib with other QT prolonging agents. Obtain an electrocardiogram (ECG) and monitor serum calcium, magnesium, and potassium levels at baseline and regular intervals in patients receiving concurrent therapy with ceritinib and another agent that prolongs the QTc interval.(1) In patients who develop a QTC interval greater than 500 msec on at least 2 occasions, withhold ceritinib until the QTc interval is less than 481 msec or recovery to baseline if baseline QTc was greater than or equal to 481 msec, then resume ceritinib with a 150 mg dose reduction. If the patient develops QTc interval prolongation in combination with torsades de pointes or polymorphic ventricular tachycardia or signs/symptoms of serious arrhythmia, permanently discontinue ceritinib.(1) Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: In a clinical trial 3% of patients experienced a QTc interval increase over baseline greater than 60 msec. Less than 1% of patients (1 of 304) treated with ceritinib was found to have a QTc greater than 500 msec. The upper limit of the 90% confidence interval for mean QTC increase was 16 msec at ceritinib 750 mg. Data suggested that ceritinib produces concentration-dependent QTc interval prolongation.(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(3) |
ZYKADIA |
| Crizotinib/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The use of crizotinib in patients maintained on agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: Consider periodic electrocardiogram (ECG) and electrolyte monitoring (calcium, magnesium, and potassium levels at baseline and regular intervals) in patients receiving concurrent therapy with crizotinib and another agent that prolongs the QTc interval.(1) In patients who develop a QTc greater than 500 ms on at least 2 separate ECGs, withhold crizotinib until recovery to baseline or to a QTc less than 481 ms, then resume crizotinib at reduced dose.(1) In patients who develop a QTc greater than 500 ms or greater than or equal to 60 ms change from baseline with Torsade de pointes or polymorphic ventricular tachycardia or signs/symptoms of serious arrhythmia, permanently discontinue crizotinib.(1) Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Crizotinib is associated with concentration-dependent QTc interval prolongation. In a clinical trial 2.1% of patients were found to have a QTcF greater than or equal to 500 msec and 5% of patients had an increase in QTcF by greater than or equal to 60 msec.(1) A retrospective review of 618 cancer patients treated with 902 administrations of tyrosine kinase inhibitors were evaluated for rate and incidence of QTc prolongation. In patients who received crizotinib, QTc prolongation was identified in 1 (50%) with 1 (100%) having Grade 1 (QTc 450-480 ms). No patients had a QTc change greater than or equal to 60 ms, ventricular tachycardia, sudden cardiac death, or TdP.(3) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(4) |
XALKORI |
| Lenvatinib/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: Concurrent use of lenvatinib in patients taking other medications that prolong the QT interval may result in additive QT prolongation. QT prolongation may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, hypoalbuminemia, bradycardia, female gender, or advanced age.(1,2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: Monitor electrocardiograms during concurrent therapy with lenvatinib and agents that prolong the QT interval. In a clinical trial of patients with refractory, progressive thyroid cancer, QT prolongation was reported in 9% of lenvatinib patients. Monitor and correct electrolyte abnormalities in all patients.(1) This is particularly important in lenvatinib patients as diarrhea, nausea, vomiting, and decreased appetite are common side effects which may increase the risk for electrolyte disturbances. Monitor ECG at baseline and at regular intervals. Lenvatinib dose must be withheld if the QTc exceeds 500 msec until QTc resolves to less than 480 msec or baseline. Lenvatinib must be resumed at reduced dose when QTc prolongation resolves to less than 480 ms or to baseline. Dose adjustments below are indication specific and are for patients with normal hepatic and renal function:(1) Dose Modifications in Differentiated Thyroid Cancer(DTC): - First occurrence of QTc > 500 msec or onset of another Grade 2 or Grade 3 Adverse Reaction or Grade 4 Laboratory Abnormality: Interrupt therapy until resolved to Grade 0-1 or baseline then decrease dose to 20 mg once daily - Second occurrence of QTc > 500 msec or onset of another Grade 2 or Grade 3 Adverse Reaction or Grade 4 Laboratory Abnormality: Interrupt therapy until resolved to Grade 0-1 or baseline then decrease dose to 14 mg once daily - Third occurrence of QTc > 500 msec or onset of another Grade 2 or Grade 3 Adverse Reaction or Grade 4 Laboratory Abnormality: Interrupt therapy until resolved to Grade 0-1 or baseline then decrease dose 10 mg once daily Dose Modifications in Renal Cell Cancer (RCC): - First occurrence of QTc > 500 msec or onset of another Grade 2 or Grade 3 Adverse Reaction or Grade 4 Laboratory Abnormality: Interrupt therapy until resolved to Grade 0-1 or baseline then decrease dose to 14 mg once daily - Second occurrence of QTc > 500 msec or onset of another Grade 2 or Grade 3 Adverse Reaction or Grade 4 Laboratory Abnormality: Interrupt therapy until resolved to Grade 0-1 or baseline then decrease dose to 10 mg once daily - Third occurrence of QTc > 500 msec or onset of another Grade 2 or Grade 3 Adverse Reaction or Grade 4 Laboratory Abnormality: Interrupt therapy until resolved to Grade 0-1 or baseline then decrease dose 8 mg once daily Dose Modifications in Hepatocellular Carcinoma (HCC) for Actual weight 60 kg or greater: - First occurrence of QTc > 500 msec or onset of another Grade 2 or Grade 3 Adverse Reaction or Grade 4 Laboratory Abnormality: Interrupt therapy until resolved to Grade 0-1 or baseline then decrease dose to 8 mg once daily - Second occurrence of QTc > 500 msec or onset of another Grade 2 or Grade 3 Adverse Reaction or Grade 4 Laboratory Abnormality: Interrupt therapy until resolved to Grade 0-1 or baseline then decrease dose to 4 mg once daily - Third occurrence of QTc > 500 msec or onset of another Grade 2 or Grade 3 Adverse Reaction or Grade 4 Laboratory Abnormality: Interrupt therapy until resolved to Grade 0-1 or baseline then decrease dose 4 mg every other day Dose Modifications in Hepatocellular Carcinoma (HCC) for Actual weight less than 60 kg: - First occurrence of QTc > 500 msec or onset of another Grade 2 or Grade 3 Adverse Reaction or Grade 4 Laboratory Abnormality: Interrupt therapy until resolved to Grade 0-1 or baseline then decrease dose to 4 mg once daily - Second occurrence of QTc > 500 msec or onset of another Grade 2 or Grade 3 Adverse Reaction or Grade 4 Laboratory Abnormality: Interrupt therapy until resolved to Grade 0-1 or baseline then decrease dose to 4 mg every other day - Third occurrence of QTc > 500 msec or onset of another Grade 2 or Grade 3 Adverse Reaction or Grade 4 Laboratory Abnormality: Interrupt therapy until resolved to Grade 0-1 or baseline and discontinue lenvatinib (1) Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: In a clinical trial of patients with refractory, progressive thyroid cancer, QT prolongation was reported in 9% of lenvatinib patients and 2% of placebo patients. The incidence of Grade 3 QT prolongation of > 500 msec was reported in 2% of lenvatinib patients compared with no reports in placebo patients.(1) In contrast, a single lenvatinib dose of 32 mg (1.3 times the recommended daily dose) did not prolong the QT/QTc interval in a thorough QT study performed in healthy subjects.(1) A retrospective review of 618 cancer patients treated with 902 administrations of tyrosine kinase inhibitors were evaluated for rate and incidence of QTc prolongation. In patients who received lenvatinib, QTc prolongation was identified in 9 (42.9%) with 4 (44.4%) having Grade 1 (QTc 450-480 ms) and 3 (33.3%) having Grade 2 (QTc 480-500 ms). Grade 3 events occurred in 0 (0%) having QTc greater than or equal to 500 ms and 1 (11.1%) having QTc change greater than or equal to 60 ms. Ventricular tachycardia was seen in 1 (11.1%) patient.(3) |
LENVIMA |
| Ondansetron/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1-3) CLINICAL EFFECTS: The use of ondansetron in patients maintained on agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1-3) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or in the elderly (> or = 75 years of age).(4) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(4) PATIENT MANAGEMENT: The risk for QT prolongation due to ondansetron is dose and route related. Intravenous (IV) doses lead to higher peak concentrations and systemic exposure and so have a greater risk for QT prolongation compared with the same dose given orally. Faster rates of IV infusion are also associated with a greater risk for QT prolongation.(5) If concomitant therapy is needed, correct electrolyte abnormalities prior to starting therapy. Monitor closely, particularly in patients with predisposing risk factors for QT prolongation (e.g. cardiac disease, female, elderly). Electrocardiogram (ECG) monitoring should be performed in patients receiving concurrent therapy.(1-3) The Canadian manufacturer of Zofran injection has specific recommendations for use of IV ondansetron in oncology patients greater than or equal to 75 years of age (5): - all IV doses must be diluted in 50 - 100 mL of compatible fluid and infused over at least 15 minutes - initial and repeat IV doses must not exceed 8 mg. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: In a double-blind, randomized, placebo and positive controlled cross-over study, an ondansetron intravenous (IV) dose of 32 mg increased the maximum mean QTcF by 19.6 msec (upper limit of 90% CI: 21.5). A dose of 8mg increased the QTcF by a maximum mean of 5.8 (upper limit of 90% CI: 7.8). A dose of 16 mg was predicted to have a mean increase in QTcF of 9.1 msec (upper limit of 90% CI: 11.2).(1) QT prolongation and torsades de pointes have been reported in post-marketing reports in patients receiving ondansetron.(2-3) In a review of published reports of QT prolongation associated with ondansetron administration, 67% of patients were also receiving another medication known to prolong the QT interval.(6) In a prospective, observational study, administration of a single ondansetron IV dose of 4 mg in the emergency department increased the mean and median QTc interval by 16.2 msec (95% CI 4.2-28.2 msec; p=0.01) and 12 msec (IQR 5.5-18 msec; p<0.01), respectively. Three patients had extreme QTc prolongation. With exclusion of those 3 patients, the median QTc prolongation was 10 msec (IQR 5-15 msec; p<0.01).(7) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(8) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
ONDANSETRON HCL, ONDANSETRON HCL-0.9% NACL |
| Romidepsin/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Romidepsin has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of romidepsin with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: The US manufacturer of romidepsin states that appropriate cardiovascular monitoring, such as baseline and regular monitoring of ECG and obtaining serum calcium, magnesium, and potassium levels, should be performed if concurrent therapy with agents known to prolong the QT interval is warranted.(1) Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: In two clinical trials, discontinuation of romidepsin secondary to QT prolongation occurred in at least 2% of patients.(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(3) |
ISTODAX, ROMIDEPSIN |
| Sorafenib/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Concurrent use of sorafenib with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The use of sorafenib patients maintained on agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: Patients receiving concurrent therapy with agents known to prolong the QTc interval should be monitored with electrocardiograms during treatment with sorafenib. Electrolytes (calcium, magnesium, and potassium) should also be monitored.(1) Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: In a non-randomized trial in 53 patients, sorafenib resulted in a mean change in QTc of 8.5 msec (upper bound of 90% CI: 13.3 msec).(1) A retrospective review of 618 cancer patients treated with 902 administrations of tyrosine kinase inhibitors were evaluated for rate and incidence of QTc prolongation. In patients who received sorafenib, QTc prolongation was identified in 13 (31.7%) with 5 (38.5%) having Grade 1 (QTc 450-480 ms) and 4 (30.7%) having Grade 2 (QTc 480-500 ms). Grade 3 events occurred in 2 (15.4%) having QTc greater than or equal to 500 ms and 2 (15.4%) having QTc change greater than or equal to 60 ms. No patients developed ventricular tachycardia, sudden cardiac death, or TdP.(3) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(4) |
NEXAVAR, SORAFENIB |
| Telavancin/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Telavancin has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of telavancin with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: The US manufacturer of telavancin recommends against the use of telavancin with other drugs known to cause QT prolongation.(1) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: In a randomized, double-blind, multiple-dose, positive-controlled, placebo-controlled, parallel study in healthy subjects, the mean maximum baseline-corrected, placebo-corrected QTc prolongation was 11.6 msec and 15.1 msec for telavancin at dosages of 7.5 mg/kg and 15 mg/kg, respectively. The estimated mean maximum baseline-corrected, placebo-corrected QTc prolongation for a telavancin dosage of 10 mg/kg is 12-15 msec.(1) In studies in patients, 21% of patients receiving telavancin (214 of 1029, 10 mg/kg) and 16% of patients receiving vancomycin (164 of 1033) received concurrent QT prolonging agents. The rate of QTc prolongation greater than 60 msec was 1.5% (15 patients) in the telavancin group and 0.6% (6 patients) in the vancomycin group. Nine of the 15 telavancin subjects with QTc prolongation received concurrent QT prolongers, compared with 1 of the vancomycin patients.(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(3) |
VIBATIV |
| Vemurafenib/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The use of vemurafenib in patients maintained on agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: Vemurafenib should not be initiated in patients taking medications known to prolong the QT interval, patients having a baseline QTc greater than 500 msec, uncorrectable electrolyte abnormalities, or known long QT syndrome is not recommended.(1) All patients receiving vemurafenib should undergo ECG testing at baseline, after 15 days of treatment, monthly during the first 3 months of treatment, and then every 3 months. If a patient's QTc exceeds 500 msec during treatment, vemurafenib should be discontinued and cardiac risk factors for QT prolongation should be controlled. Consider discontinuing other medications known to prolong the QT interval at this time. If the patient's QTc decreases below 500 msec, vemurafenib may be introduced at a lower dosage according to the current labeling recommendations. If the patient's QTc remains greater than 500 msec and increased >60 msec from pre-treatment values after controlling cardiac risk factors for prolongation, permanently discontinue vemurafenib.(1) Consider obtaining serum calcium, magnesium, and potassium levels at baseline and regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Vemurafenib is associated with concentration-dependent QTc interval prolongation. In the first month of treatment, the largest mean QTc change was 12.8 msec (upper boundary of 90% CI: 14.9 msec). In the first 6 months of treatment, the largest mean QTc change was 15.1 msec (upper boundary of 90% CI: 17.7 msec).(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(3) |
ZELBORAF |
| Pimavanserin/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Pimavanserin prolongs the QTc interval.(1) Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(2,3) CLINICAL EFFECTS: The concurrent use of pimavanserin with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(2,3) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(3) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(3) PATIENT MANAGEMENT: Avoid the use of pimavanserin in patients receiving QT prolonging agents.(1) During concomitant therapy with another QT prolonging agent, monitor patients closely for prolongation of the QT interval.(1) Obtain serum calcium, magnesium, and potassium levels and monitoring ECG at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: In thorough-QT study, pimavanserin (at twice the therapeutic dose) found that the maximum mean change was 13.5 (16.6) msec. In placebo-controlled effectiveness studies, mean increases of 5-8 msec were observed with normal dosages of 37 mg daily. Sporadic QTcF values of equal to or greater than 500 msec and change from baseline values equal to or greater than 60 msec were observed at this dose as well.(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(2) |
NUPLAZID |
| Hydroxyzine/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Concurrent use of hydroxyzine with agents that prolong the QTc interval may result in additive effects on the QTc interval.(1-4) CLINICAL EFFECTS: The concurrent use of hydroxyzine with agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1-4) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(5) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, and/or renal/hepatic dysfunction).(5) Doses of hydroxyzine greater than 100 mg/day may also increase the risk.(1,2) PATIENT MANAGEMENT: Concurrent use of hydroxyzine with agents known to prolong the QT interval is contraindicated in Canada(1,2) and the UK.(3) The US manufacturer states that concurrent use should be approached with caution.(4) If concurrent therapy is deemed medically necessary, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: In vitro data indicates that hydroxyzine blocks the hERG channel, which results in the potential risk of QT interval prolongation.(6) In a placebo controlled, non-thorough QT study, 10 patients in the placebo group (n=152) had a change in QT interval from baseline between 30 ms and 60 ms and one patient presented a change from baseline higher than 60 ms. In the hydroxyzine group (n=148), 14 subjects had a change in QT interval from baseline between 30 and 60 ms and were considered to have a potential risk factor for risk of QT interval prolongation and TdP due to relevant medical history, concomitant medication potentially associated with the induction of prolongation of QT interval, and/or polymedication.(6) Health Canada reviewed 61 cases of QT interval prolongation or torsades de pointes with hydroxyzine. In a majority of cases, patients had additional risk factors for QT prolongation. Three reports provided enough data for a more detailed review. Hydroxyzine was found to be either "possible" or "probably" contribution to QT prolongation/torsades in these reports.(1) The European Medicines Agency's Pharmacovigilance Risk Assessment Committee (PRAC) reviewed 190 case reports found in a search of "torsade de pointes/QT prolongation with hydroxyzine". Forty-two non-fatality cases were subdivided into torsades (n=16), QT prolongation (n=21), and ventricular tachycardia (n=5). All included risk factors for QT interval prolongation and TdP (cardiac disorders, hypokalemia, long QT syndrome, bradycardia, concomitant drugs which are known to prolong the QT interval). Dosages ranged from <= 100 mg/day (n=10), > 100 mg/day to <=300 mg/day (n=4), > 300 mg/day (n=8), overdosages (n=11), and premedication (n=9). Twenty-one cases involving fatalities had at least one risk factor for QT prolongation. The PRAC concluded that post-marketing cases of QT interval prolongation, TdP and ventricular tachycardia confirm the findings of the hERG studies suggesting that hydroxyzine blocks hERG channels. No difference in the risk of QT interval prolongation could be observed based on the indication, age of the subject, or dose.(6) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(7) |
HYDROXYZINE HCL, HYDROXYZINE PAMOATE |
| Opioids (Cough and Cold)/Antipsychotics; Phenothiazines SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Concurrent use of opioids and antipsychotics, including phenothiazine derivatives, may result in additive CNS depression.(1) CLINICAL EFFECTS: Concurrent use of opioids and other CNS depressants, such as antipsychotics, including phenothiazine derivatives, may result in profound sedation, respiratory depression, coma, and/or death.(1) PREDISPOSING FACTORS: Concurrent use of alcohol or other CNS depressants may increase the risk of adverse effects. PATIENT MANAGEMENT: Avoid prescribing opioid-including cough medications for patients taking CNS depressants such as antipsychotics, including phenothiazine derivatives.(1) Respiratory depression can occur at any time during opioid therapy, especially during therapy initiation and following dosage increases. Consider this risk when using concurrently with other agents that may cause CNS depression.(2) If concurrent use is necessary, monitor patients for unusual dizziness or lightheadedness, extreme sleepiness, slowed or difficult breathing, or unresponsiveness.(1) Discuss naloxone with all patients when prescribing or renewing an opioid analgesic or medicine to treat opioid use disorder (OUD). Consider prescribing naloxone to patients prescribed medicines to treat OUD or opioid analgesics (such as those taking CNS depressants) who are at increased risk of opioid overdose and when a patient has household members/close contacts at risk for accidental overdose.(3) DISCUSSION: A nested case-control study looked at the relationship between antipsychotic use and risk of acute respiratory failure. Current use of antipsychotics was associated with a 2.33-fold increase in risk of respiratory failure compared to no use of antipsychotics. The risk was also significantly increased in patients with recent use of antipsychotics (within the past 15-30 days, OR = 1.79) and recent past use (within 31-90 days OR = 1.41). The risk increased with higher doses and longer duration of use.(4) Between 2002 and 2014, the number of patients receiving an opioid analgesic increased 8%, from 75 million to 81 million patients, and the number of patients receiving a benzodiazepine increased 31%, from 23 million to 30 million patients. During this time, the proportion of patients receiving concurrent therapy increased 31%, from 23 million to 30 million patients.(5) From 2004 to 2011, the rate of nonmedical use-related emergency room visits involving both opioids and benzodiazepines increased from 11 to 34.2 per 100,000 and drug overdose deaths involving both opioids and benzodiazepines increased from 0.6 to 1.7 per 100,000. The proportion of prescription opioid analgesic deaths which also involved benzodiazepines increased from 18% to 31% during this time.(6) A prospective observational cohort study in North Carolina found that the rates of overdose death among patients co-dispensed opioid analgesics and benzodiazepines were 10 times higher than patients receiving opioid analgesics alone.(7) A case-cohort study of VA data from 2004-2009 found that the risk of death from overdose increased with concomitant opioid analgesics and benzodiazepines. Compared to patients with no history of benzodiazepines, patients with a history of benzodiazepine use (hazard ratio [HR] = 2.33) and patients with a current benzodiazepine prescription (HR=3.86) had an increased risk of fatal overdose.(8) A study found that opioid analgesics contributed to 77% of deaths in which benzodiazepines were determined to be a cause of death and that benzodiazepines contributed to 30% of deaths in which opioid analgesics were determined to be a cause of death. This study also found that other CNS depressants (including barbiturates, antipsychotic and neuroleptic drugs, antiepileptic and antiparkinsonian drugs, anesthetics, autonomic nervous system drugs, and muscle relaxants) were contributory to death in many cases where opioid analgesics were also implicated.(9) A study found that alcohol was involved in 18.5% of opioid analgesic abuse-related ED visits and 22.1 percent of opioid analgesic-related deaths.(10) |
HYCODAN, HYDROCODONE-CHLORPHENIRAMNE ER, HYDROCODONE-HOMATROPINE MBR, HYDROMET, PROMETHAZINE-CODEINE, TUXARIN ER |
| Ribociclib/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Concurrent use of ribociclib with agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of ribociclib with agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: Avoid concurrent use of ribociclib with agents known to prolong the QT interval.(1) If concurrent therapy is deemed medically necessary, monitor patients closely. Obtain serum calcium, magnesium, and potassium levels and correct any electrolyte abnormalities at the beginning of each ribociclib cycle. Monitor ECG at baseline, Day 14 of the first cycle, at the beginning of the second cycle, and as necessary. If a prolonged QTc is noted, refer to ribociclib prescribing information for current dose modification and management instructions. Ribociclib may need to be interrupted, reduced, or discontinued.(1) Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Ribociclib has been shown to prolong the QTc interval in a concentration-dependent manner. At steady state, the mean increase in QTc interval exceeded 20 msec.(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(3) |
KISQALI |
| Hydroxychloroquine/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Hydroxychloroquine has been observed to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of hydroxychloroquine with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: The US manufacturer of hydroxychloroquine states that hydroxychloroquine should not be administered with other agents that prolong the QT interval.(1) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: The manufacturer states that hydroxychloroquine has been shown to prolong the QT interval;(1) however, conditions that hydroxychloroquine treats have also been associated with QT prolongation. Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(3) |
HYDROXYCHLOROQUINE SULFATE, PLAQUENIL, SOVUNA |
| Inotuzumab Ozogamicin/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Concurrent use of inotuzumab ozogamicin with agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of inotuzumab ozogamicin with agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: When possible, discontinue QT prolonging agents prior to therapy with inotuzumab ozogamicin or use alternative agents during inotuzumab ozogamicin therapy.(1) When concurrent therapy cannot be avoided, obtain ECGs and electrolyte values (serum calcium, magnesium, and potassium) prior to the start of treatment, after initiation of any drug known to prolong the QT interval, and periodically monitor during therapy.(1) Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting.(1) DISCUSSION: Inotuzumab ozogamicin was shown to prolong the QT interval in clinical trials. In the INO-VATE trial, 3% (4/162) of patients experienced an increase in QTc equal to or greater than 60 msec. No patients has QTc values greater than 500 msec. Grade 2 QT prolongation was reported in 1% (2/164) patients. There were no reports of Grade 3 QT prolongation or Torsade de Pointes.(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(3) |
BESPONSA |
| Lofexidine/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Lofexidine has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1,2) CLINICAL EFFECTS: Concurrent use of lofexidine and agents known to prolong the QT interval may exacerbate QT prolongation.(1,2) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, advanced age,(3) renal impairment, and/or hepatic impairment.(1,2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(3) PATIENT MANAGEMENT: The UK manufacturer of lofexidine states that concurrent use of lofexidine and QT prolonging agents should be avoided.(1) The US manufacturer states that ECGs should be monitored in patients receiving concurrent therapy with lofexidine and agents that are known to prolong the QT interval.(2) Consider obtaining serum calcium, magnesium, and potassium levels at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: In a study of healthy volunteers, lofexidine 1.44 mg to 1.8 mg had a change from baseline in QTc of 14.4 msec and 13.6 msec, respectively.(2) In a dose response study, lofexidine had a mean QTc prolongation of 7.3 msec and 9.3 msec at doses of 2.16 mg/day and 2.88 mg/day, respectively.(2) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(4) |
LOFEXIDINE HCL, LUCEMYRA |
| Glasdegib/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Concurrent use of glasdegib with agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of glasdegib with agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: Avoid the concurrent use of glasdegib with medications that prolong the QT interval.(1) When concurrent therapy cannot be avoided, obtain ECGs and electrolyte values (serum calcium, magnesium, and potassium) prior to the start of treatment, after initiation of any drug known to prolong the QT interval, and periodically monitor during therapy. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. If QTc prolongation develops: ---Monitor and supplement electrolytes as clinically indicated ---Review and adjust concomitant QT prolonging medications ---Interrupt glasdegib therapy for QTc interval greater than 500 ms. ---Monitor ECGs at least weekly for 2 weeks following resolution of QTc prolongation ---Follow labeling recommendations regarding restarting glasdegib.(1) DISCUSSION: In a randomized, single-dose, double-blind, 4-way cross-over, placebo- and open-label moxifloxacin-controlled study in 36 healthy subjects, the largest placebo and baseline-adjusted QTc interval change was 8 msec (90% CI: 6-10 msec) with a single 150 mg dose of glasdegib (The 150 mg single dose was used to achieve therapeutic plasma concentrations). With two-fold therapeutic plasma concentrations (achieved with a 300 mg single dose), the QTc change was 13 msec (90% CI: 11-16 msec).(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(3) |
DAURISMO |
| Entrectinib/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Concurrent use of entrectinib with agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of entrectinib with agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: Avoid the concurrent use of entrectinib with medications that prolong the QT interval.(1) When concurrent therapy cannot be avoided, obtain ECGs and electrolyte values (serum calcium, magnesium, and potassium) prior to the start of treatment, after initiation of any drug known to prolong the QT interval, and periodically monitor during therapy. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. If QTc prolongation develops: ---Monitor and supplement electrolytes as clinically indicated ---Review and adjust concomitant QT prolonging medications ---Interrupt entrectinib therapy for QTc interval greater than 500 ms. ---Follow labeling recommendations regarding restarting entrectinib.(1) If torsade de pointes, polymorphic ventricular tachycardia, and/or signs/symptoms of serious arrhythmia occur, permanently discontinue entrectinib.(1) DISCUSSION: In clinical trials, 3.1% of patients with at least one post-baseline ECG experienced QTcF prolongation of greater than 60 msec after starting entrectinib..(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(3) |
ROZLYTREK |
| Lefamulin/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Concurrent use of lefamulin with agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of lefamulin with agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: Avoid the concurrent use of lefamulin with medications that prolong the QT interval.(1) When concurrent therapy cannot be avoided, obtain ECGs and electrolyte values (serum calcium, magnesium, and potassium) prior to the start of treatment, after initiation of any drug known to prolong the QT interval, and periodically monitor during therapy. Correct any electrolyte abnormalities.(1) Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: In a thorough QT study, intravenous lefamulin increased the QTcF 13.6 msec (90% CI = 15.5 msec) and oral lefamulin increased the QTcF by 9.3 msec (90% CI = 10.9 msec).(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(3) |
XENLETA |
| Methadone for MAT/Selected Antipsychotics that Prolong QT SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Methadone has been shown to prolong the QTc interval. Concurrent use with selected antipsychotics may result in additive effects on the QTc interval.(1-3) Concurrent use of methadone and antipsychotics may result in additive CNS depression.(1-3) CLINICAL EFFECTS: The concurrent use of methadone with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1,2) Concurrent use of opioids and other CNS depressants such as antipsychotics may result in profound sedation, respiratory depression, coma, and/or death.(1-3) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(4) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(4) Concurrent use of alcohol or other CNS depressants may increase the risk of adverse effects. PATIENT MANAGEMENT: Concurrent use of methadone with other agents known to prolong the QT interval should be approached with extreme caution.(1,2) Limit prescribing methadone with CNS depressants such as antipsychotics to patients for whom alternatives are inadequate.(3) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. Medication assisted treatment (MAT) with methadone is not contraindicated in patients taking CNS depressants; however, gradual tapering or decreasing to the lowest effective dose of antipsychotics may be appropriate. Ensure that other health care providers prescribing other CNS depressants are aware of the patient's methadone treatment.(5) If concurrent use is necessary, limit the dosages and duration of each drug to the minimum possible while achieving the desired clinical effect. If starting a CNS depressant (for an indication other than epilepsy) with an opioid analgesic, prescribe a lower initial dose of the CNS depressant than indicated in the absence of an opioid and titrate based upon clinical response. If an opioid analgesic is indicated in a patient already taking a CNS depressant, prescribe a lower dose of the opioid and titrate based upon clinical response.(3) Respiratory depression can occur at any time during opioid therapy, especially during therapy initiation and following dosage increases. Consider this risk when using concurrently with other agents that may cause CNS depression.(6) Monitor patients receiving concurrent therapy for unusual dizziness or lightheadedness, extreme sleepiness, slowed or difficult breathing, or unresponsiveness.(3) Discuss naloxone with all patients when prescribing or renewing an opioid analgesic or medicine to treat opioid use disorder (OUD). Consider prescribing naloxone to patients prescribed medicines to treat OUD or opioid analgesics (such as those taking CNS depressants) who are at increased risk of opioid overdose and when a patient has household members/close contacts at risk for accidental overdose.(7) DISCUSSION: Most cases of methadone-induced QT prolongation are associated with, but not limited to, higher dose treatment (greater than 200 mg daily) and most involve patients being treated for pain with large, multiple daily doses. Cases have been reported in patients treated with doses commonly used for maintenance treatment of opioid addiction.(2) Levomethadone should be used with caution in patients with a history of QT prolongation, advanced heart disease, concomitant CYP3A4 inhibitors, or electrolyte abnormalities. Cases of QT prolongation and torsades de pointes have been reported, most commonly with high doses.(1) A nested case-control study looked at the relationship between antipsychotic use and risk of acute respiratory failure. Current use of antipsychotics was associated with a 2.33-fold increase in risk of respiratory failure compared to no use of antipsychotics. The risk was also significantly increased in patients with recent use of antipsychotics (within the past 15-30 days, OR = 1.79) and recent past use (within 31-90 days OR = 1.41). The risk increased with higher doses and longer duration of use.(8) Between 2002 and 2014, the number of patients receiving an opioid analgesic increased 8%, from 75 million to 81 million patients, and the number of patients receiving a benzodiazepine increased 31%, from 23 million to 30 million patients. During this time, the proportion of patients receiving concurrent therapy increased 31%, from 23 million to 30 million patients.(9) From 2004 to 2011, the rate of nonmedical use-related emergency room visits involving both opioids and benzodiazepines increased from 11 to 34.2 per 100,000 and drug overdose deaths involving both opioids and benzodiazepines increased from 0.6 to 1.7 per 100,000. The proportion of prescription opioid analgesic deaths which also involved benzodiazepines increased from 18% to 31% during this time.(10) A prospective observational cohort study in North Carolina found that the rates of overdose death among patients co-dispensed opioid analgesics and benzodiazepines were 10 times higher than patients receiving opioid analgesics alone.(11) A case-cohort study of VA data from 2004-2009 found that the risk of death from overdose increased with concomitant opioid analgesics and benzodiazepines. Compared to patients with no history of benzodiazepines, patients with a history of benzodiazepine use (hazard ratio [HR] = 2.33) and patients with a current benzodiazepine prescription (HR=3.86) had an increased risk of fatal overdose.(12) A study found that opioid analgesics contributed to 77% of deaths in which benzodiazepines were determined to be a cause of death and that benzodiazepines contributed to 30% of deaths in which opioid analgesics were determined to be a cause of death. This study also found that other CNS depressants (including barbiturates, antipsychotic and neuroleptic drugs, antiepileptic and antiparkinsonian drugs, anesthetics, autonomic nervous system drugs, and muscle relaxants) were contributory to death in many cases where opioid analgesics were also implicated.(13) A study found that alcohol was involved in 18.5% of opioid analgesic abuse-related ED visits and 22.1 percent of opioid analgesic-related deaths.(14) Selected antipsychotics that prolong QT include: amsulpride, chlorpromazine, chlorprothixene, clozapine, haloperidol, iloperidone, mesoridazine, paliperidone, pimavanserin, pipamperone, promethazine, quetiapine, sulpiride, sultopride, thioridazine, ziprasidone, and zuclopenthixol. |
DISKETS, METHADONE HCL, METHADONE INTENSOL, METHADOSE |
| Methadone (non MAT)/Selected Antipsychotics that Prolong QT SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Methadone has been shown to prolong the QTc interval. Concurrent use with selected antipsychotics may result in additive effects on the QTc interval. Concurrent use of methadone and antipsychotics may result in additive CNS depression.(1,2) CLINICAL EFFECTS: Concurrent use of methadone with antipsychotics may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) Concurrent use of methadone and other CNS depressants such as antipsychotics may result in profound sedation, respiratory depression, coma, and/or death.(1,2) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(3) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(3) Concurrent use of alcohol or other CNS depressants may increase the risk of adverse effects. PATIENT MANAGEMENT: Concurrent use of methadone with agents known to prolong the QT interval should be approached with extreme caution.(1) Limit prescribing methadone with CNS depressants such as antipsychotics to patients for whom alternatives are inadequate.(2) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. If concurrent use is necessary, limit the dosages and duration of each drug to the minimum possible while achieving the desired clinical effect. If starting a CNS depressant (for an indication other than epilepsy) with an opioid analgesic, prescribe a lower initial dose of the CNS depressant than indicated in the absence of an opioid and titrate based upon clinical response. If an opioid analgesic is indicated in a patient already taking a CNS depressant, prescribe a lower dose of the opioid and titrate based upon clinical response.(2) Respiratory depression can occur at any time during opioid therapy, especially during therapy initiation and following dosage increases. Consider this risk when using concurrently with other agents that may cause CNS depression.(4) Discuss naloxone with all patients when prescribing or renewing an opioid analgesic or medicine to treat opioid use disorder (OUD). Consider prescribing naloxone to patients prescribed medicines to treat OUD or opioid analgesics (such as those taking CNS depressants) who are at increased risk of opioid overdose and when a patient has household members/close contacts at risk for accidental overdose.(5) DISCUSSION: Most cases of methadone-induced QT prolongation are associated with, but not limited to, higher dose treatment (greater than 200 mg daily) and most involve patients being treated for pain with large, multiple daily doses. Cases have been reported in patients treated with doses commonly used for maintenance treatment of opioid addiction.(1) A nested case-control study looked at the relationship between antipsychotic use and risk of acute respiratory failure. Current use of antipsychotics was associated with a 2.33-fold increase in risk of respiratory failure compared to no use of antipsychotics. The risk was also significantly increased in patients with recent use of antipsychotics (within the past 15-30 days, OR = 1.79) and recent past use (within 31-90 days OR = 1.41). The risk increased with higher doses and longer duration of use.(6) Between 2002 and 2014, the number of patients receiving an opioid analgesic increased 8%, from 75 million to 81 million patients, and the number of patients receiving a benzodiazepine increased 31%, from 23 million to 30 million patients. During this time, the proportion of patients receiving concurrent therapy increased 31%, from 23 million to 30 million patients.(7) From 2004 to 2011, the rate of nonmedical use-related emergency room visits involving both opioids and benzodiazepines increased from 11 to 34.2 per 100,000 and drug overdose deaths involving both opioids and benzodiazepines increased from 0.6 to 1.7 per 100,000. The proportion of prescription opioid analgesic deaths which also involved benzodiazepines increased from 18% to 31% during this time.(8) A prospective observational cohort study in North Carolina found that the rates of overdose death among patients co-dispensed opioid analgesics and benzodiazepines were 10 times higher than patients receiving opioid analgesics alone.(9) A case-cohort study of VA data from 2004-2009 found that the risk of death from overdose increased with concomitant opioid analgesics and benzodiazepines. Compared to patients with no history of benzodiazepines, patients with a history of benzodiazepine use (hazard ratio [HR] = 2.33) and patients with a current benzodiazepine prescription (HR=3.86) had an increased risk of fatal overdose.(10) A study found that opioid analgesics contributed to 77% of deaths in which benzodiazepines were determined to be a cause of death and that benzodiazepines contributed to 30% of deaths in which opioid analgesics were determined to be a cause of death. This study also found that other CNS depressants (including barbiturates, antipsychotic and neuroleptic drugs, antiepileptic and antiparkinsonian drugs, anesthetics, autonomic nervous system drugs, and muscle relaxants) were contributory to death in many cases where opioid analgesics were also implicated.(11) A study found that alcohol was involved in 18.5% of opioid analgesic abuse-related ED visits and 22.1 percent of opioid analgesic-related deaths.(12) Selected antipsychotics linked include: amsulpride, chlorpromazine, chlorprothixene, clozapine, iloperidone, mesoridazine, paliperidone, perphenazine, pimavanserin, pipamperone, promethazine, quetiapine, sulpiride, sultopride, thioridazine, ziprasidone, and zuclopenthixol. |
METHADONE HCL, METHADONE HCL-0.9% NACL, METHADONE HCL-NACL |
| Oxaliplatin/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Concurrent use of oxaliplatin with agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of oxaliplatin with agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: Avoid the concurrent use of oxaliplatin in patients with congenital long QT syndrome. ECG monitoring is recommended if oxaliplatin therapy is initiated in patients with congestive heart failure, bradyarrhythmias, drugs known to prolong the QT interval, and electrolyte abnormalities.(1) When concurrent therapy cannot be avoided, obtain ECGs and electrolyte values (serum calcium, magnesium, and potassium) prior to the start of treatment, after initiation of any drug known to prolong the QT interval, and periodically monitor during therapy. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Prescribing information for oxaliplatin states post-marketing cases of QT prolongation and ventricular arrhythmias, including fatal Torsades de Pointes, have been reported.(1) Case reports have documented QT prolongation in patients with varying cancer indications for oxaliplatin.(3-6) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(7) |
OXALIPLATIN |
| Selpercatinib/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Selpercatinib prolongs the QTc interval.(1) Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(2,3) CLINICAL EFFECTS: The concurrent use of selpercatinib with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(2,3) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(3) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(3) PATIENT MANAGEMENT: Selpercatinib prolongs the QT interval. An increase in QT interval to > 500 ms was measured in 6% of patients and increase in the QT interval of at least 60 ms over baseline was measured in 15% of patients. Monitor patients at significant risk of developing QT prolongation, including patients with known long QT syndromes, clinically significant bradyarrhythmias, and severe or uncontrolled heart failure. Assess QT interval, electrolytes, and TSH at baseline and periodically during treatment. Correct hypokalemia, hypomagnesemia, and hypocalcemia prior to initiation and during treatment. Dose adjustments (1): For grade 3 QT interval prolongation, withhold selpercatinib until recovery to baseline or grade 0 or 1. Resume at a reduced dose. -1st dose reduction: For patients weighing less than 50 kg: 80 mg twice daily. For patients weighing 50 kg or greater: 120 mg twice daily. -2nd dose reduction: For patients weighing less than 50 kg: 40 mg twice daily. For patients weighing 50 kg or greater: 80 mg twice daily. -3rd dose reduction: For patients weighing less than 50 kg: 40 mg once daily. For patients weighing 50 kg or greater: 40 mg twice daily. -For grade 4 QT prolongation, discontinue selpercatinib. DISCUSSION: The effect of selpercatinib on the QT interval was evaluated in a thorough QT study in healthy subjects. The largest mean increase in QT is predicted to be 10.6 ms (upper 90% confidence interval: 12.1 ms) at the mean steady state maximum concentration (Cmax) observed in patients after administration of 160 mg twice daily. The increase in QT was concentration-dependent. Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(2) |
RETEVMO |
| Pazopanib/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Pazopanib has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of pazopanib with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(3) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, and/or renal/hepatic dysfunction).(3) PATIENT MANAGEMENT: The US manufacturer of pazopanib states that pazopanib should be avoided in patients receiving other drugs known to cause QT prolongation.(1) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: In clinical studies, 2% (11/558) of patients receiving pazopanib experienced QT prolongation. Torsades de pointes occurred in less than 1% (2/977) of patients who received pazopanib in monotherapy studies. In a randomized clinical trial, 3 of 290 patients who received pazopanib had post-baseline QTc values between 500 and 549 msec. None of the patients receiving placebo had post-baseline QTc values greater than or equal to 500 msec.(1) A retrospective review of 618 cancer patients treated with 902 administrations of tyrosine kinase inhibitors were evaluated for rate and incidence of QTc prolongation. In patients who received pazopanib, QTc prolongation was identified in 32 (19.4%) with 18 (56.3%) having Grade 1 (QTc 450-480 ms) and 4 (12.5%) having Grade 2 (QTc 480-500 ms). Grade 3 events occurred in 3 (9.3%) having QTc greater than or equal to 500 ms and 4 (12.5%) having QTc change greater than or equal to 60 ms. Ventricular tachycardia was seen in 2 (6.3%) of patients and 1 (3.1%) patient experienced sudden cardiac death.(4) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(2) |
PAZOPANIB HCL, VOTRIENT |
| Apomorphine/Selected Antipsychotics that Prolong QT SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Concurrent use of apomorphine with certain antipsychotics may have additive effects on the QTc interval.(1) In addition, apomorphine is used to treat Parkinson Disease (PD) by increasing dopamine concentrations at D2 receptors in the central nervous system (CNS). Antipsychotic agents counteract this effect by blocking dopamine activity at CNS D2 receptors.(1,2) CLINICAL EFFECTS: The concurrent use of apomorphine with certain antipsychotics may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) In addition, the efficacy of either agent may be decreased, leading to exacerbation of PD. Motor symptoms may worsen, increasing the risk for falls, dysphagia or aspiration.(3) Compared with Parkinson patients not receiving antipsychotic therapy, Parkinson patients receiving antipsychotics appear to have an increased mortality risk.(2) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age. Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(4) Patients with Parkinson or Diffuse Lewy Body (DLB) disease are particularly susceptible to adverse effects of dopamine blockade by antipsychotics. PATIENT MANAGEMENT: The US manufacturer of apomorphine states that patients with major psychotic disorders treated with neuroleptics should be treated with dopamine agonists only if the potential benefits outweigh the risks. Concurrent use with agents known to prolong the QT interval should be approached with caution.(1) The Canadian manufacturer of levomepromazine states concomitant use with other QT prolonging medications is not recommended.(5) The UK manufacturer of zuclopenthixol states that coadministration of other QT prolonging medications should be avoided.(6) Manufacturers of other QT-prolonging antipsychotics generally recommend using caution when coadministered with medications that prolong the QT interval. Reassess the need for antipsychotic therapy. If psychosis or hallucinations are due to an antiparkinson agent, when possible consider reducing the dose or changing the antiparkinson agent before initiating antipsychotic therapy. In patients with PD and dementia, addition of a cholinesterase inhibitor (e.g. rivastigmine) may improve psychosis. If an antipsychotic is required, then an atypical antipsychotic should be used.(2,3) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: An epidemiologic study evaluated 21,043 elderly patients with Parkinson disease to determine if recent initiation of a typical or atypical antipsychotic was associated with increased mortality. They found an adjusted odds ratio of 2.0 for death associated with atypical antipsychotics versus no antipsychotic. They also found an adjusted odds ratio of 2.4 for death associated with typical versus atypical antipsychotics. The authors noted the increased mortality found with typical antipsychotics supports current treatment recommendations to use atypical antipsychotic agents in patients with Parkinson disease.(3,4) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(7) |
APOKYN, APOMORPHINE HCL, ONAPGO |
| Selected Dopamine Agonists/Slt Antipsychotics SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Selected dopamine agonists are used to treat neurologic conditions such as Parkinson Disease (PD) or restless legs syndrome, and endocrine disorders such as hyperprolactinemia by directly or indirectly increasing dopamine concentrations at D2 receptors in the central nervous system (CNS). Antipsychotic agents counteract this effect by blocking dopamine activity at CNS D2 receptors.(1-5) CLINICAL EFFECTS: The efficacy of either agent may be decreased, leading to exacerbation of the disease being treated. In patients with Parkinson disease motor symptoms may worsen, increasing the risk for falls, dysphagia or aspiration.(4,7) Compared with Parkinson patients not receiving antipsychotic therapy, Parkinson patients receiving antipsychotics appear to have an increased mortality risk.(6) Patients with other conditions such as restless legs syndrome or a psychotic disorder may also experience symptom exacerbation due to this combination. PREDISPOSING FACTORS: Patients with Parkinson or Diffuse Lewy Body (DLB) disease are particularly susceptible to adverse effects of dopamine blockade by antipsychotics. PATIENT MANAGEMENT: Reassess the need for antipsychotic therapy. If psychosis or hallucinations are due to an antiparkinson agent, when possible consider reducing the dose or changing the antiparkinson agent before initiating antipsychotic therapy. In patients with PD and dementia, addition of a cholinesterase inhibitor (e.g. rivastigmine) may improve psychosis. If an antipsychotic is required, then an atypical antipsychotic should be used.(6,7) In patients with major psychotic disorders, consider reducing the dose, changing or stopping the dopamine agonist. The US manufacturer of ropinirole recommends treatment with dopamine agonists only if potential benefits outweigh risks.(1) The US manufacturer of entacapone states it should not ordinarily be used in patients with major psychotic disorders as entacapone may lead to an exacerbation of psychosis.(4) DISCUSSION: An epidemiologic study evaluated 21,043 elderly patients with Parkinson disease to determine if recent initiation of a typical or atypical antipsychotic was associated with increased mortality. They found an adjusted odds ratio of 2.0 for death associated with atypical antipsychotics versus no antipsychotic They found an adjusted odds ratio of 2.4 for death associated with typical versus atypical antipsychotics. The authors noted the increased mortality found with typical antipsychotics supports current treatment recommendations to use atypical antipsychotic agents in patients with Parkinson disease.(6,7) |
BROMOCRIPTINE MESYLATE, CARBIDOPA-LEVODOPA, CARBIDOPA-LEVODOPA ER, CARBIDOPA-LEVODOPA-ENTACAPONE, CREXONT, CYCLOSET, DHIVY, DUOPA, INBRIJA, LEVODOPA, MIRAPEX ER, NEUPRO, PRAMIPEXOLE DIHYDROCHLORIDE, PRAMIPEXOLE ER, ROPINIROLE ER, ROPINIROLE HCL, RYTARY, SINEMET, VYALEV |
| Haloperidol/Strong CYP3A4 Inducers that Prolong QT SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Strong CYP3A4 inducers may increase the metabolic clearance of haloperidol.(1-3) Haloperidol can prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in an additive risk of QT prolongation.(1-4) CLINICAL EFFECTS: Coadministration with strong CYP3A4 inducers may result in decreased levels and effectiveness of haloperidol. Coadministration with other QT prolonging agents may cause additive effects on the QTc interval, which may result in life-threatening cardiac arrhythmias including torsades de pointes.(1-4) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(4) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(4) Induction effects may be more likely with regular use of the inducer for longer than 1-2 weeks. PATIENT MANAGEMENT: Monitor clinical response in patients maintained on haloperidol when initiating or discontinuing strong CYP3A4 inducers. The dosage of haloperidol may need to be adjusted.(1) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: In a study in 11 schizophrenic patients, the addition of carbamazepine resulted in a dose related decrease in haloperidol levels. Haloperidol levels were decreased by 2%, 61%, and 85%, respectively, from baseline following the addition and increase of carbamazepine at 100 mg/day, 300 mg/day, and 600 mg/day.(1,5) In a study in 27 patients with schizophrenia or schizoaffective disorder, the use of haloperidol with carbamazepine was associated with lower haloperidol levels and worse clinical outcomes than the use of haloperidol alone.(6) In a study in schizophrenic patients, haloperidol levels were significantly decreased in patients receiving concurrent carbamazepine.(7) In a study in 7 patients, haloperidol levels fell 60% following the addition of carbamazepine to therapy. Haloperidol levels were undetectable in 2 subjects, whose symptoms worsened.(8) In a study in 23 patients, the addition of carbamazepine to haloperidol resulted in improvement in symptoms.(9) In a retrospective review of 231 schizophrenic patients, patients receiving concurrent carbamazepine or phenobarbital had haloperidol levels that were 37% and 22% lower, respectively, than patients taking haloperidol without these agents.(10) In a study in 6 schizophrenic patients, switching carbamazepine to oxcarbazepine resulted in increased in haloperidol levels by 50% to 200% after 2-4 weeks of therapy.(11) In a study in schizophrenic patients, carbamazepine decreased haloperidol levels by 50%. One subject developed worsening of symptoms, while two improved.(12) There are also case reports documenting decreased haloperidol levels and effectiveness with concurrent carbamazepine.(13-17) In a study in schizophrenic patients, the addition of rifampin in 12 patients resulted in decreases in haloperidol levels by 37%, 58.7%, and 70% by Day 3, Day 7, and Day 28, respectively, of concurrent therapy. Mean scores on the Brief Psychiatric Rating Scale decreased from baseline. Discontinuation of rifampin from concurrent therapy in 5 patients increased haloperidol levels by 140.7%, 228.7%, and 329% of baseline by Day 3, Day 7, and Day 28, respectively, after rifampin discontinuation.(1,18) In a study in 7 schizophrenic patients, rifampin decreased the half-life of haloperidol by 48%.(19) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(20) Strong CYP3A4 inducers that prolong QT linked to this monograph include: encorafenib and ivosidenib.(2,3) |
BRAFTOVI, TIBSOVO |
| Panobinostat/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Panobinostat has been observed to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of panobinostat with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: The manufacturer of panobinostat states concurrent use agents known to prolong the QT interval are not recommended. Panobinostat should not be started in patients with a QTcF > 450 msec or clinically significant baseline ST-segment or T-wave abnormalities. If during panobinostat therapy the QTcF increases to > 480 msec, interrupt treatment and correct any electrolyte abnormalities. If QT prolongation does not resolve, permanently discontinue treatment with panobinostat.(1) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: In the randomized multiple myeloma trial, QTc prolongation with values between 451 msec to 480 msec occurred in 10.8% of panobinostat treated patients and patients with values of 481 msec to 500 msec occurred in 1.3% of patients. A maximum QTcF increase from baseline of between 31 msec and 60 msec was reported in 14.5% of patients and a maximum QTcF increase from baseline of >60 msec was reported in 0.8% of patients.(1) Pooled clinical data from over 500 patients treated with single agent panobinostat in multiple indications and at different dose levels has shown that the incidence of CTC Grade 3 QTc prolongation (QTcF >500 msec) was approximately 1% overall and 5% or more at a dose of 60 mg or higher.(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(3) |
FARYDAK |
| Pacritinib/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Pacritinib has been observed to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of pacritinib with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: The manufacturer of pacritinib states concurrent use with agents known to prolong the QT interval should be avoided. Avoid the use of pacritinib in patients with a baseline QTc > 480 msec. Correct hypokalemia prior to initiation and during therapy with pacritinib.(1) If patients develop QTc prolongation >500 msec or >60 msec from baseline, hold pacritinib. If QTc prolongation resolves to <=480 msec or to baseline within 1 week, resume pacritinib at the same dose. If time to resolution of the QTc interval takes greater than 1 week to resolve, reduce the pacritinib dose.(1) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: In a 24 week clinical study, patients treatment with pacritinib 200 mg twice daily had a change in QTc from baseline of 11 msec (90% CI: 5-17).(1) Pacritinib has been associated with QTc interval prolongation. In clinical trials, patients with QTc prolongation >500 msec occurred in 1.4% of patients in the treatment arm compared to 1% in the control arm. The treatment arm had a greater incidence of an increase in QTc > 60 msec from baseline than the control arm (1.9% vs 1%, respectively). QTc prolongation adverse reactions were higher in the treatment arm than the control group (3.8% vs 2%, respectively).(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(3) |
VONJO |
| Haloperidol/Adagrasib SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Haloperidol is metabolized via many metabolic pathways. The contributions of CYP2D6, CYP3A4 and possibly CYP1A2 pathways are most clearly defined. Concomitant use of haloperidol with inhibitors of one or more of these pathways may lead to clinically significant increases in haloperidol levels and result in additive QT effects of the QTc interval. Adagrasib is a strong CYP3A4 inhibitor and a moderate CYP2D6 inhibitor.(1,2) CLINICAL EFFECTS: The concurrent administration of adagrasib may result in elevated levels of haloperidol and lead to toxicities such as orthostatic hypotension, akathisia, acute dystonia, or Parkinsonism. Concurrent use may also result in additive QTc prolongation, which may lead to life-threatening cardiac arrhythmias like torsade de pointes.(1,2) PREDISPOSING FACTORS: Elderly patients, particularly those with a history of falls or swallowing disorders, and patients with Parkinson Disease, Lewy Body Disease, or other dementias are more sensitive to antipsychotics and have a greater risk for adverse effects. Younger patients, patients on low doses of haloperidol, or on a dose targeted to lower-therapeutic serum levels, have a lower interaction risk. The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(3) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(3) The risk of anticholinergic toxicities including cognitive decline, delirium, falls and fractures is increased in geriatric patients using more than one medicine with anticholinergic properties.(4) PATIENT MANAGEMENT: The manufacturer of adagrasib states that concurrent use with QT prolonging agents, sensitive CYP2D6 substrates with a narrow therapeutic window, or sensitive CYP3A4 substrates should be avoided.(2) Monitor patient for extrapyramidal side effects and orthostatic hypotension if adagrasib is added to haloperidol therapy and lower haloperidol dose if needed.(1) When concurrent therapy cannot be avoided, obtain ECGs and electrolyte values (serum calcium, magnesium, and potassium) prior to the start of treatment, after initiation of any drug known to prolong the QT interval, and periodically monitor during therapy. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. If patients develop QTc prolongation >500 msec or >60 msec from baseline, withhold adagrasib until QTc interval less than 481 msec or QTc interval returns to baseline. Resume adagrasib at the next lower dose level. If patients develop torsade de pointes, polymorphic ventricular tachycardia, or signs and symptoms of serious or life-threatening arrythmia, permanently discontinue adagrasib.(1) DISCUSSION: Although it is an older agent, the complex pharmacokinetics of haloperidol are not yet fully understood. Adagrasib has been associated with QTc interval prolongation. Adagrasib increased QTc in a concentration-dependent manner. In patients administered adagrasib 600 mg twice daily, the mean QTcF change from baseline was 18 msec. In the pooled safety population, 6% of 366 patients with at least one post-baseline ECG had an average QTc greater than 501 msec and 11% of patients had a increase from baseline QTc greater than 60 msec.(1) |
KRAZATI |
| Quizartinib/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Quizartinib has been shown to prolong the QTc interval in a dose- and concentration dependent manner. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1-3) CLINICAL EFFECTS: The concurrent use of quizartinib with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1-3) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: The US manufacturer of quizartinib states that the concurrent use of QT prolonging agents should be avoided.(1) Quizartinib is only available through a restricted REMS program due to the serious risk of QT prolongation, torsades de pointes, and cardiac arrest. The manufacturer recommends monitoring as follows: -Initiate quizartinib only if the QTcF is less than or equal to 450 ms. -During induction and consolidation, monitor ECGs prior to initiation and then at minimum once weekly during treatment. -During maintenance, monitor ECGs prior to initiation and then at minimum once weekly for the first month following dose initiation and escalation and clinically therafter. Dose escalation may occur only if the QTcF is less than or equal to 450 ms. The manufacturer recommends the following dose modifications for adverse reactions: -If the QTcF is 450 ms to 480 ms (Grade 1) - Continue quizartinib dose. -If the QTcF is 481 ms to 500 ms (Grade 2) - Reduce the dose of quizartinib without interruption based on prescribing information. Resume the previous dose in the next cycle if the QTcF has decreased to less than 450 ms. -If the QTcF is greater than 500 ms (Grade 3) - Interrupt quizartinib. Resume at a reduced dose based on prescribing information when the QTcF is less than 450 ms. Maintain the dose of 26.5 mg once daily during maintenance if the QTcF is greater than 500 ms during induction or consolidation. -If recurrent QTcF is greater than 500 ms (Grade 3) - Permanently discontinue quizartinib if QTcF is greater than 500 ms despite dose reduction and correction/elimination of other risk factors. -If TdP, polymorphic ventricular tachycardia, or signs/symptoms of life-threatening arrythmia occur (Grade 4) - Permanently discontinue quizartinib. When concurrent therapy cannot be avoided, obtain ECGs and electrolyte values (serum calcium, magnesium, and potassium) prior to the start of treatment, after initiation of any drug known to prolong the QT interval, and periodically monitor during therapy. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Quizartinib has been associated with QTc interval prolongation, Torsades de Pointes, ventricular arrhythmias, cardiac arrest, and sudden death. Quizartinib increased QTc in a dose- and concentration-dependent manner.(1) In an exposure-response analysis, quizartinib had a predicted concentration-dependent QTc prolongation of 18 to 24 ms (upper bound of 2-sided 90% CI: 21 and 27 ms) at a median steady-state Cmax dose of 26.5 mg and 53 mg during maintenance therapy.(1) In patients administered quizartinib, 2.3% of 265 patients had a QTcF greater than 500 msec and 10% of patients had a increase from baseline QTcF greater than 60 msec.(1) In patients administered quizartinib during the induction phase, torsades de pointes occurred in approximately 0.2% of patients, cardiac arrest occurred in 0.6%, including 0.4% with a fatal outcome, and 0.1% of patients experienced ventricular fibrillation.(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(3) |
VANFLYTA |
| Dexmedetomidine Sublingual/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Dexmedetomidine sublingual has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of dexmedetomidine sublingual with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: The manufacturer of dexmedetomidine sublingual states that concurrent use should be avoided with other agents known to prolong the QTc interval.(1) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: In a QT study, dexmedetomidine sublingual had a concentration dependent effect on the QT interval. The mean QTc (95% confidence interval) increased from baseline by 6 (7) msec with a 120 mcg single dose, 8 (9) msec with 120 mcg followed by 2 additional doses of 60 mcg (total 3 doses), 8 (11) msec with a single 180 mcg dose, and 11 (14) msec with 180 mcg followed by 2 additional doses of 90 mcg (total 3 doses), respectively.(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(3) |
IGALMI |
| Glucagon (Diagnostic)/Anticholinergics SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Glucagon and anticholinergic agents may have additive effects on inhibition of gastrointestinal motility.(1) CLINICAL EFFECTS: Concurrent use of glucagon with anticholinergic agents may increase the risk of gastrointestinal hypomotility, including constipation and bowel complications.(1) PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: Concurrent use of glucagon as a diagnotic aid is not recommended with the use of anticholinergic agents.(1) If concurrent use is necessary, evaluate the patient's bowel function. Monitor for symptoms of constipation and gastrointestinal hypomotility. DISCUSSION: Both glucagon and anticholinergic agents may have additive effects on inhibition of gastrointestinal motility and increase the risk of gastrointestinal adverse effects.(1) |
GLUCAGON HCL |
| Lonafarnib/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Lonafarnib has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of lonafarnib with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: The manufacturer of lonafarnib states that the concurrent use of QT prolonging agents should be avoided. If concurrent use cannot be avoided, obtain ECGs when initiating, during concurrent use, and as clinically indicated.(1) Lonafarnib dose modification recommendation: if the QTc interval is greater than or equal to 500 msec, withhold lonafarnib until the QTc interval is less than 470 msec, then resume lonafarnib at the same dosage.(1) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities.(1) Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: In a thorough QT study, lonafarnib 200 mg twice daily for 9 consecutive days and a single 200 mg dose on day 10 increased the mean QTc interval by 19 msec (upper bound of 90% confidence interval = 27 msec) on day 10 at 48 hours after administration of the morning dose of lonafarnib 200 mg. The maximum concentration (Cmax) on Day 10 was 2233 ng/ml, which is similar to the mean Cmax of 2695 ng/ml observed in the Hutchinson-Gilford Progeria Syndrome patient population.(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(3) |
ZOKINVY |
| Givinostat/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Givinostat may prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of givinostat with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: The manufacturer of givinostat states that the concurrent use of QT prolonging agents should be avoided. If concurrent use cannot be avoided, obtain ECGs prior to initiating givinostat, during concomitant use, and as clinically indicated.(1) If the QTc interval is greater than 500 ms or the change from baseline is greater than 60 ms, withhold givinostat therapy.(1) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities.(1) Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: In a QT study, the largest mean increase in QTc interval of 13.6 ms (upper confidence interval of 17.1 ms) occurred 5 hours after administration of givinostat 265.8 mg (approximately 5 times the recommended 53.2 mg dose in patients weighing 60 kg or more).(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(3) |
DUVYZAT |
| Revumenib/QT Prolonging Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Revumenib may prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of revumenib with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: The manufacturer of revumenib states that the concurrent use of QT prolonging agents should be avoided. If concurrent use cannot be avoided, obtain ECGs prior to initiating revumenib, during concomitant use, and as clinically indicated.(1) If the QTc interval is greater than 480 ms, withhold revumenib therapy. Resume revumenib after the QTc interval drops to 480 msec or less.(1) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities.(1) Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: In clinical trials, QTc interval prolongation was reported as an adverse event in 29% of 135 patients treated with the recommended dosage of revumenib; 12% of patients had Grade 3 QTc prolongation. Revumenib increased the QTc interval in a concentration-dependent manner. At the mean steady-state Cmax using the highest approved recommended dosage of revumenib without CYP3A4 inhibitors, QTc increase was predicted to be 27 msec (upper bound of 90% confidence interval = 30 msec). At the steady-state Cmax using the highest approved recommended dosage of revumenib with CYP3A4 inhibitors, QTc increase was predicted to be 19 msec (upper bound of 90% confidence interval = 22 msec).(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(3) |
REVUFORJ |
There are 41 moderate interactions.
The clinician should assess the patient’s characteristics and take action as needed. Actions required for moderate interactions include, but are not limited to, discontinuing one or both agents, adjusting dosage, altering administration.
| Drug Interaction | Drug Names |
|---|---|
| Guanethidine; Guanadrel/Phenothiazines SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Phenothiazines may inhibit uptake of guanethidine at the adrenergic neuron. CLINICAL EFFECTS: Decreased antihypertensive effectiveness. Effects may be seen for several days after discontinuation of the phenothiazine. PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: Avoid concomitant administration of these drugs. If both drugs are administered, adjust the guanethidine dose as needed based on blood pressure. Consider giving molindone in place of the phenothiazine. Available data indicate that hydralazine or minoxidil do not interact with phenothiazines. Severe hypertension was reported in one patient during concurrent use of methyldopa and the phenothiazine trifluoperazine. However, this interaction was not substantiated in animals. DISCUSSION: Documentation supports routine monitoring of this interaction. The antihypertensive effect of guanethidine/guanadrel usually reverses over several days to more than one week after starting concurrent phenothiazine and guanethidine therapy. When the phenothiazine is stopped, an initial rebound increase in blood pressure may occur. |
GUANETHIDINE HEMISULFATE |
| Selected Antipsychotics/Lithium SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: The exact mechanism of the interaction is unknown. Neurotoxicity symptoms (confusion, delirium, seizures, encephalopathy, and EEG changes) may be due to potentiation or an additive effect of the antipsychotic agent and lithium. CLINICAL EFFECTS: Concurrent use of lithium and selected antipsychotic agents may produce neurotoxic symptoms, including extrapyramidal symptoms, neuroleptic malignant syndrome, and encephalopathic syndrome. PREDISPOSING FACTORS: Large doses of either drug, pre-existing brain damage or other conditions (e.g. infection, dehydration) may increase the risk for neurotoxicity. PATIENT MANAGEMENT: Lithium and antipsychotic agents are commonly co-prescribed for the acute management of manic or mixed manic episodes associated with bipolar disorder. Concurrent use should be approached with caution. Consider additional clinical monitoring for signs and symptoms of neurotoxicity, including confusion, fever, lethargy, tremors, stupor, weakness, leukocytosis, and increased blood urea nitrogen. If signs of neurotoxicity appear, discontinuation of the antipsychotic agent may be required. The US manufacturer of lithium carbonate states concurrent use with antipsychotic agents, including chlorpromazine, clozapine, fluphenazine, haloperidol, perphenazine, risperidone, and thioridazine, should be monitored closely. Although uncommon to rare, cases of severe neurotoxicity have been reported with this combination. Monitoring plasma levels is not always beneficial in preventing neurotoxic symptoms. Patients may experience neurotoxic symptoms with plasma concentrations in the therapeutic ranges. Close monitoring for signs of neurotoxicity, EEG monitoring, adequate hydration, and electrolyte status are recommended to minimize toxic potential. DISCUSSION: Lithium and antipsychotic agents are commonly co-prescribed for the acute management of manic or mixed manic episodes associated with bipolar disorder. Several case reports have been published describing acute and irreversible neurotoxicity with the combination of lithium and antipsychotic agents, though these episodes often resemble rare serious events that can be attributed to the administration of either agent alone (e.g., delirium, dysphoria, encephalopathy, dyskinesias, neuroleptic malignant syndrome, etc.). Signs and symptoms of neurotoxicity associated with concomitant use have included confusion, fever, lethargy, tremors, stupor, weakness, leukocytosis, and increased blood urea nitrogen. Extrapyramidal effects, which in some cases were irreversible, and permanent brain damage have also been reported. Selected antipsychotics linked to this monograph include: benperidol, clozapine, haloperidol, and risperidone. |
LITHIUM CARBONATE, LITHIUM CARBONATE ER, LITHIUM CITRATE, LITHIUM CITRATE TETRAHYDRATE, LITHOBID |
| Bupropion/Antipsychotics SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Both bupropion and the antipsychotics are known to lower the seizure threshold.(1,2) Bupropion is also a strong inhibitor of CYP2D6.(3) CLINICAL EFFECTS: Concurrent use of bupropion and an antipsychotic may result in additive effects on the seizure threshold, increasing the risk of seizures.(1,2) PREDISPOSING FACTORS: The risk of seizures may be increased in patients with a history of head trauma or prior seizure; CNS tumor; severe hepatic cirrhosis; excessive use of alcohol or sedatives; addiction to opiates, cocaine, or stimulants; use of over-the-counter stimulants an anorectics; a total daily dose of bupropion greater than 450 mg or single doses greater than 150 mg; rapid escalation of bupropion dosage; diabetics treated with oral hypoglycemics or insulin; or with concomitant medications known to lower seizure threshold (antidepressants, theophylline, systemic steroids).(1,2) The risk of anticholinergic toxicities including cognitive decline, delirium, falls and fractures is increased in geriatric patients using more than one medicine with anticholinergic properties.(3) PATIENT MANAGEMENT: The concurrent use of bupropion and antipsychotics should be undertaken only with extreme caution and with low initial bupropion dosing and small gradual dosage increases.(1,2) Single doses should not exceed 150 mg.(1,2) The maximum daily dose of bupropion should not exceed 300 mg for smoking cessation(2) or 450 mg for depression.(1) DISCUSSION: Because of the risk of seizure from concurrent bupropion and other agents that lower seizure threshold, the manufacturer of bupropion states that the concurrent use of bupropion and antipsychotics should be undertaken only with extreme caution and with low initial bupropion dosing and small gradual dosage increases.(1) |
APLENZIN, AUVELITY, BUPROPION HCL, BUPROPION HCL SR, BUPROPION XL, CONTRAVE, FORFIVO XL, WELLBUTRIN SR, WELLBUTRIN XL |
| Gatifloxacin/QT Prolonging Agents SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Gatifloxacin has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of gatifloxacin with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes. congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(3) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(3) PATIENT MANAGEMENT: The manufacturer of gatifloxacin states that gatifloxacin should be used with caution when given with other agents known to prolong the QT interval, including erythromycin, phenothiazines, and tricyclics.(1) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(2) |
GATIFLOXACIN SESQUIHYDRATE |
| Haloperidol/QT Prolonging Agents SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Torsades de pointes has been reported with haloperidol. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1-3) CLINICAL EFFECTS: The concurrent use of haloperidol with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1-3) PREDISPOSING FACTORS: The risk of QT prolongation may be increased by: hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, use of multiple medications, intravenous haloperidol, or higher than recommended dosages of haloperidol. The risk of QT prolongation or torsade de pointes may also be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), bradycardia, or advanced age.(5) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(5) PATIENT MANAGEMENT: The Australian,(1) UK(2) and US(3) manufacturers of haloperidol state that haloperidol should be used with caution when given with other agents known to prolong the QT interval. If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Sudden death, QT-prolongation, and torsades de pointes have been reported with haloperidol.(3) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(4) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
ADVAIR DISKUS, ADVAIR HFA, AIRDUO DIGIHALER, AIRDUO RESPICLICK, ALFUZOSIN HCL ER, ASTAGRAF XL, ATOMOXETINE HCL, CESIUM CHLORIDE, CLOZAPINE, CLOZAPINE ODT, CLOZARIL, DASATINIB, ELLENCE, ENVARSUS XR, EPIRUBICIN HCL, FLUTICASONE-SALMETEROL, FLUTICASONE-SALMETEROL HFA, GRANISETRON HCL, ISRADIPINE, LAPATINIB, LEVOFLOXACIN, LEVOFLOXACIN HEMIHYDRATE, LEVOFLOXACIN-D5W, OFLOXACIN, PROGRAF, QUETIAPINE FUMARATE, QUETIAPINE FUMARATE ER, RUBRACA, RYDAPT, SANCUSO, SEREVENT DISKUS, SEROQUEL, SEROQUEL XR, SPRYCEL, STRATTERA, SUNITINIB MALATE, SUSTOL, SUTENT, TACROLIMUS, TACROLIMUS XL, TYKERB, UROXATRAL, VERSACLOZ, WIXELA INHUB |
| Ranolazine/QT Prolonging Agents SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Ranolazine prolongs the QTc interval in a dose-related manner. Use with other agents that prolong the QTc interval may result in additive effects.(1) CLINICAL EFFECTS: Concurrent use of ranolazine and agents known to prolong the QTc interval may result in prolongation of the QTc interval and life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(4) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(4) PATIENT MANAGEMENT: The UK manufacturer of ranolazine states that concurrent use with agents known to prolong the QT interval should be approached with caution.(1) Patients should be instructed to inform their physician if they are receiving any drugs that prolong the QTc interval.(2) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Ranolazine has been shown to prolong the QTc interval in a dose-related manner.(1,2) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(3) |
ASPRUZYO SPRINKLE, RANOLAZINE ER |
| Posaconazole/QT Prolonging Agents SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Concurrent use of posaconazole and agents known to prolong the QT interval may result in additive or synergistic effects on the QTc Interval.(1) CLINICAL EFFECTS: Concurrent administration may result in prolongation of the QTc interval and life-threatening cardiac arrhythmias, including torsades de pointes. PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(3) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(3) PATIENT MANAGEMENT: The UK manufacturer of posaconazole states that posaconazole should be used with caution when given with other agents known to prolong the QT interval.(1) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(2) |
NOXAFIL, POSACONAZOLE |
| Ciprofloxacin/QT Prolonging Agents SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Ciprofloxacin has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of ciprofloxacin with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(4) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, and/or renal/hepatic dysfunction).(4) PATIENT MANAGEMENT: The US manufacturer of ciprofloxacin states that ciprofloxacin should be used with caution with other agents known to prolong the QT interval, especially in the elderly.(1) The UK manufacturer of ciprofloxacin states that ciprofloxacin should be used with caution in patients at risk for torsades.(2) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(3) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
CIPRO, CIPROFLOXACIN, CIPROFLOXACIN HCL, CIPROFLOXACIN-D5W |
| Voriconazole/QT Prolonging Agents SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Concurrent use of voriconazole with agents known to prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: Concurrent use may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes. PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: The manufacturer of voriconazole states concurrent use with agents known to prolong the QT interval should be administered with caution.(1) In patients maintained on voriconazole and other agents known to prolong the QT interval, consider a baseline ECG prior to administration to assess the risk/benefit of therapy. Consider obtaining serum calcium, magnesium, and potassium levels at baseline and at regular intervals. Correct any electrolyte abnormalities prior to initiation of therapy. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: A placebo-controlled, randomized, crossover study to evaluate the effect on the QT interval of healthy male and female subjects was conducted with three single oral doses of voriconazole and ketoconazole. The placebo-adjusted mean maximum increases in QTc from baseline after 800 mg, 1200 mg, and 1600 mg of voriconazole and after ketoconazole 800 mg were all <10 msec. No subject experienced an interval exceeding the potentially clinically relevant threshold of 500 msec.(1) In a retrospective study of 2,735 patients with a prolonged QTc interval, voriconazole use was associated with an increased risk of torsades de pointes.(4) |
VFEND, VFEND IV, VORICONAZOLE |
| Fingolimod/QT Prolonging Agents SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Fingolimod is a sphingosine 1-phosphate (S1P) receptor modulator. Initiation of fingolimod has a negative chronotropic effect leading to a mean decrease in heart rate of 13 beats per minute (bpm) after the first dose. The first dose has also been associated with heart block.(1-3) Fingolimod blocks the capacity of lymphocytes to egress from lymph nodes, reducing the number of lymphocytes in peripheral blood. The mechanism by which fingolimod exerts therapeutic effects in multiple sclerosis is unknown but may involve the reduction of lymphocyte migration into the central nervous system.(1-3) CLINICAL EFFECTS: The heart rate lowering effect of fingolimod is biphasic with an initial decrease usually within 6 hours, followed by a second decrease 12 to 24 hours after the first dose. Symptomatic bradycardia and heart block, including third degree block, have been observed. Bradycardia may be associated with an increase in the QTc interval, increasing the risk for torsades de pointes. There is no consistent signal of increased incidence of QTc outliers, either absolute or change from baseline, associated with fingolimod treatment.(1-3) PREDISPOSING FACTORS: Pre-existing cardiovascular or cerebrovascular disease (e.g. heart failure, ischemic heart disease, history of myocardial infarction, stroke, or heart block), severe untreated sleep apnea, a prolonged QTc interval prior to fingolimod initiation, factors associated with QTc prolongation (e.g. hypokalemia, hypomagnesemia), or concomitant treatment with QT prolonging agents may increase risk for cardiovascular toxicity due to fingolimod. The risk of QT prolongation or torsades de pointes may also be increased in patients with a history of torsades de pointes, hypocalcemia, bradycardia, female gender, or advanced age.(4) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of the QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(4) PATIENT MANAGEMENT: Patients with a baseline QTc interval greater than or equal to 500 milliseconds should not be started on fingolimod. Patients with pre-existing cardiovascular or cerebrovascular disease (e.g. heart failure, ischemic heart disease, history of myocardial infarction, stroke, or heart block), severe untreated sleep apnea, or a prolonged QTc interval prior to fingolimod initiation should receive cardiologist consultation to evaluate the risks of fingolimod therapy. In all patients, first dose monitoring is recommended to monitor for bradycardia for the first 6 hours. Check blood pressure and pulse hourly. ECG monitoring is recommended prior to dosing and at the end of the observation period. US monitoring recommendations include additional monitoring for the following patients:(1) If heart rate (HR) is less than 45 beats per minute (bpm), the heart rate 6 hours postdose is at the lowest value postdose, or if the ECG shows new onset of second degree or higher AV block at the end of the monitoring period, then monitoring should continue until the finding has resolved. Continuous overnight ECG monitoring is recommended in patients requiring pharmacologic intervention for symptomatic bradycardia, some preexisting heart and cerebrovascular conditions, prolonged QTc before dosing or during 6 hours observation, concurrent therapy with QT prolonging drugs, or concurrent therapy with drugs that slow heart rate or AV conduction. Consult the prescribing information for full monitoring recommendations. United Kingdom recommendations:(3) Obtain a 12-lead ECG prior to initiating fingolimod therapy. Consult a cardiologist for pretreatment risk-benefit assessment if patient has a resting heart rate less than 55 bpm, history of syncope, second degree or greater AV block, sick-sinus syndrome, concurrent therapy with beta-blockers, Class Ia, or Class III antiarrhythmics, heart failure or other significant cardiovascular disease. Perform continuous ECG monitoring, measure blood pressure and heart rate every hour, and perform a 12-lead ECG 6 hours after the first dose. Monitoring should be extended beyond 6 hours if symptomatic bradycardia or new onset of second degree AV block, Mobitz Type II or third degree AV block has occurred at any time during the monitoring period. If heart rate 6 hours after the first dose is less than 40 bpm, has decreased more than 20 bpm compared with baseline, or if a new onset second degree AV block, Mobitz Type I (Wenckebach) persists, then monitoring should also be continued. If fingolimod treatment is discontinued for more than two weeks, the effects on heart rate and conduction could recur. Thus, first dose monitoring precautions should be followed upon reintroduction of fingolimod. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: After the first dose of fingolimod, heart rate decrease may begin within an hour. Decline is usually maximal at approximately 6 hours followed by a second decrease 12 to 24 hours after the first dose. The second dose may further decrease heart rate, but the magnitude of change is smaller than the first dose. With continued, chronic dosing, heart rate gradually returns to baseline in about one month.(1,2) In a thorough QT interval study of doses of 1.25 or 2.5 mg fingolimod at steady-state, when a negative chronotropic effect of fingolimod was still present, fingolimod treatment resulted in a prolongation of QTc, with the upper boundary of the 90% confidence interval (CI) of 14.0 msec. The cause of death in a patient who died within 24 hour after taking the first dose of fingolimod was not conclusive; however a link to fingolimod or a drug interaction with fingolimod could not be ruled out.(1) |
FINGOLIMOD, GILENYA, TASCENSO ODT |
| Haloperidol/Fluoxetine; Fluvoxamine SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Haloperidol is metabolized via many metabolic pathways. The contributions of CYP2D6, CYP3A4 and possibly CYP1A2 pathways are most clearly defined. Concomitant use of haloperidol with inhibitors of one or more of these pathways may lead to clinically significant increases in haloperidol levels. Fluoxetine is a strong CYP2D6 inhibitor and a weak CYP3A4 inhibitor. Fluvoxamine is a strong inhibitor of CYP1A2 and CYP2C19 and is a weak inhibitor of CYP2C8, CYP2C9, and CYP3A4. CLINICAL EFFECTS: The concurrent administration of fluoxetine or fluvoxamine may result in elevated levels of haloperidol and lead to toxicities such as orthostatic hypotension, akathisia, acute dystonia, or Parkinsonism. PREDISPOSING FACTORS: Elderly patients, particularly those with a history of falls or swallowing disorders, and patients with Parkinson Disease, Lewy Body Disease, or other dementias are more sensitive to antipsychotics and have a greater risk for adverse effects. Younger patients, patients on low doses of haloperidol, or on a dose targeted to lower-therapeutic serum levels, have a lower interaction risk. PATIENT MANAGEMENT: Monitor patient for extrapyramidal side effects and orthostatic hypotension if fluoxetine or fluvoxamine is added to haloperidol therapy and lower haloperidol dose if needed. The onset and peak effects of an interaction with fluoxetine may be delayed 1 to 2 weeks due to its long 3 to 7 day half-life. DISCUSSION: Although it is an older agent, the complex pharmacokinetics of haloperidol are not yet fully understood. |
FLUOXETINE DR, FLUOXETINE HCL, FLUVOXAMINE MALEATE, FLUVOXAMINE MALEATE ER, OLANZAPINE-FLUOXETINE HCL, PROZAC |
| Pasireotide/QT Prolonging Agents SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Concurrent use of pasireotide with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The use of pasireotide patients maintained on agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(3) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(3) PATIENT MANAGEMENT: Pasireotide should be used with caution in patients receiving therapy with agents that prolong the QT interval. If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals.(1) Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: In randomized, blinded, crossover study in healthy subjects, pasireotide (0.6 mg BID) increased the placebo-subtracted QTcI by 12.7 msec (95 upper CI: 14.7 msec). Supra-therapeutic doses of 1.95 mg BID increased the placebo-subtracted QTcI by 16.6 msec (95 upper CI: 18.6 msec).(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(2) |
SIGNIFOR, SIGNIFOR LAR |
| Escitalopram/QT Prolonging Agents SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Concurrent use of multiple agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of multiple agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(1) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, and/or renal/hepatic dysfunction).(1) PATIENT MANAGEMENT: While the US FDA and manufacturer recommend no special precautions when escitalopram is used with QT prolonging agents,(2,3) Health Canada and the Canadian manufacturer of escitalopram discourage the concurrent use of agents known to prolong the QT interval(4,5) and the UK manufacturer states that concurrent use is contraindicated.(6) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(7) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
ESCITALOPRAM OXALATE, LEXAPRO |
| Sevoflurane/QT Prolonging Agents SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Concurrent use of multiple agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of multiple agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(1) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, and/or renal/hepatic dysfunction).(1) PATIENT MANAGEMENT: Sevoflurane should be used with caution in patients taking agents known to prolong the QT interval.(2) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(3) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
SEVOFLURANE, ULTANE |
| Clarithromycin/QT Prolonging Agents SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Clarithromycin may prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1-15) CLINICAL EFFECTS: The concurrent use of clarithromycin with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1-15) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(1) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, and/or renal/hepatic dysfunction).(1) PATIENT MANAGEMENT: General monitoring when concurrent therapy is warranted: consider obtaining serum calcium, magnesium, and potassium levels at baseline and regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. Agent specific recommendations: The manufacturers of apomorphine,(2) clarithromycin,(3) gatifloxacin,(4) gemifloxacin,(5) norfloxacin,(6) and sevoflurane(7) state that these agents should used with caution with other agents known to prolong the QT interval. While the US FDA and manufacturer recommend no special precautions when escitalopram is used with QT prolonging agents,(8,9) Health Canada and the Canadian manufacturer of escitalopram discourage the concurrent use of agents known to prolong the QT interval(10,11) and the UK manufacturer states that concurrent use is contraindicated.(12) The US manufacturer of ciprofloxacin states that ciprofloxacin should be used with caution with other agents known to prolong the QT interval, especially in the elderly.(13) The UK manufacturer of ciprofloxacin states that ciprofloxacin should be used with caution in patients at risk for torsades.(14) DISCUSSION: Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(15) One or more of the drug pairs linked to this monograph have been included in a list of interactions that should be considered "high-priority" for inclusion and should not be inactivated in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology. |
CLARITHROMYCIN, CLARITHROMYCIN ER, LANSOPRAZOL-AMOXICIL-CLARITHRO, OMECLAMOX-PAK |
| Eribulin/QT Prolonging Agents SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Eribulin has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of eribulin with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: The US manufacturer of eribulin states that patients receiving concurrent therapy with eribulin and other agents known to prolong the QT interval should receive ECG monitoring.(1) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: QT prolongation, independent of eribulin concentration, was observed on Day 8 of therapy but not on Day 1 in an uncontrolled open-label ECG study in 26 patients.(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(3) |
ERIBULIN MESYLATE, HALAVEN |
| Efavirenz/QT Prolonging Agents SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Efavirenz has been observed to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of efavirenz with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(2) CYP2B6 genotype may also increase the risk of this interaction. Patients who are most susceptible to this interaction are patients who are CYP2B6 poor metabolizers with CYP2B6 *6/*6 allele.(3) PATIENT MANAGEMENT: The US manufacturer of efavirenz states alternatives should be considered when concurrent administration with a drug with a known risk of Torsade de Pointes or when administered to patients at higher risk of Torsade de Pointes. Limited information is available on the potential pharmacodynamic interaction between efavirenz and drugs that prolong the QT interval; however, QT prolongation has been observed with efavirenz.(1) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: A thorough QT study was conducted in the general population in 120 healthy subjects receiving efavirenz 600 mg daily. Time-matched differences in QTc with efavirenz compared to placebo was evaluated on day 11, at 6 hours post dose. The mean change in QTc was 5.2 msec and no change in QTc was greater than 10 msec.(4) In addition to the thorough QT study, the effect of efavirenz on the QTc interval was evaluated in 58 healthy subjects based on CYP2B6 genotype. CYP2B6 polymorphism was evaluated for each patient and results were the following: 65% with *1/*1 or *1/*4 allele (wild-type metabolizers), 26% with *1/*6 allele (intermediate metabolizers) and 9% with *6/*6 allele (slow metabolizers). Subjects with 2 copies of the CYP2B6*6 allele had significantly higher efavirenz exposure at steady-state (p<0.05). At steady-state concentrations of efavirenz, patients with CYP2B6 *1/*1 or *1/*6 alleles had no change in the QTc interval (p>0.05). However, patients with CYP2B6 *6/*6 allele had an increase in QTc mean +/- SD from 406 +/- 16.4 to 423 +/- 11.8 msec (p=0.02).(3) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(5) |
EFAVIRENZ, EFAVIRENZ-EMTRIC-TENOFOV DISOP, EFAVIRENZ-LAMIVU-TENOFOV DISOP, SYMFI, SYMFI LO |
| Opioids (Extended Release)/Antipsychotics; Phenothiazines SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Concurrent use of opioids and antipsychotics, including phenothiazine derivatives, may result in additive CNS depression.(1) CLINICAL EFFECTS: Concurrent use of opioids and other CNS depressants, such as antipsychotics, including phenothiazine derivatives, may result in profound sedation, respiratory depression, coma, and/or death.(1) PREDISPOSING FACTORS: Concurrent use of alcohol or other CNS depressants may increase the risk of adverse effects. PATIENT MANAGEMENT: Limit prescribing opioid analgesics with CNS depressants such as antipsychotics, including phenothiazine derivatives, to patients for whom alternatives are inadequate.(1) If concurrent use is necessary, limit the dosages and duration of each drug to the minimum possible while achieving the desired clinical effect. If starting a CNS depressant (for an indication other than epilepsy) with an opioid analgesic, prescribe a lower initial dose of the CNS depressant than indicated in the absence of an opioid and titrate based upon clinical response. If an opioid analgesic is indicated in a patient already taking a CNS depressant, prescribe a lower dose of the opioid and titrate based upon clinical response.(1) Respiratory depression can occur at any time during opioid therapy, especially during therapy initiation and following dosage increases. Consider this risk when using concurrently with other agents that may cause CNS depression.(2) Monitor patients receiving concurrent therapy for unusual dizziness or lightheadedness, extreme sleepiness, slowed or difficult breathing, or unresponsiveness.(1) Discuss naloxone with all patients when prescribing or renewing an opioid analgesic or medicine to treat opioid use disorder (OUD). Consider prescribing naloxone to patients prescribed medicines to treat OUD or opioid analgesics (such as those taking CNS depressants) who are at increased risk of opioid overdose and when a patient has household members/close contacts at risk for accidental overdose.(3) DISCUSSION: A nested case-control study looked at the relationship between antipsychotic use and risk of acute respiratory failure. Current use of antipsychotics was associated with a 2.33-fold increase in risk of respiratory failure compared to no use of antipsychotics. The risk was also significantly increased in patients with recent use of antipsychotics (within the past 15-30 days, OR = 1.79) and recent past use (within 31-90 days OR = 1.41). The risk increased with higher doses and longer duration of use.(4) Between 2002 and 2014, the number of patients receiving an opioid analgesic increased 8%, from 75 million to 81 million patients, and the number of patients receiving a benzodiazepine increased 31%, from 23 million to 30 million patients. During this time, the proportion of patients receiving concurrent therapy increased 31%, from 23 million to 30 million patients.(5) From 2004 to 2011, the rate of nonmedical use-related emergency room visits involving both opioids and benzodiazepines increased from 11 to 34.2 per 100,000 and drug overdose deaths involving both opioids and benzodiazepines increased from 0.6 to 1.7 per 100,000. The proportion of prescription opioid analgesic deaths which also involved benzodiazepines increased from 18% to 31% during this time.(6) A prospective observational cohort study in North Carolina found that the rates of overdose death among patients co-dispensed opioid analgesics and benzodiazepines were 10 times higher than patients receiving opioid analgesics alone.(7) A case-cohort study of VA data from 2004-2009 found that the risk of death from overdose increased with concomitant opioid analgesics and benzodiazepines. Compared to patients with no history of benzodiazepines, patients with a history of benzodiazepine use (hazard ratio [HR] = 2.33) and patients with a current benzodiazepine prescription (HR=3.86) had an increased risk of fatal overdose.(8) A study found that opioid analgesics contributed to 77% of deaths in which benzodiazepines were determined to be a cause of death and that benzodiazepines contributed to 30% of deaths in which opioid analgesics were determined to be a cause of death. This study also found that other CNS depressants (including barbiturates, antipsychotic and neuroleptic drugs, antiepileptic and antiparkinsonian drugs, anesthetics, autonomic nervous system drugs, and muscle relaxants) were contributory to death in many cases where opioid analgesics were also implicated.(9) A study found that alcohol was involved in 18.5% of opioid analgesic abuse-related ED visits and 22.1 percent of opioid analgesic-related deaths.(10) |
BUPRENORPHINE, BUTRANS, CONZIP, FENTANYL, HYDROCODONE BITARTRATE ER, HYDROMORPHONE ER, HYSINGLA ER, MORPHINE SULFATE ER, MS CONTIN, NUCYNTA ER, OXYCODONE HCL ER, OXYCONTIN, OXYMORPHONE HCL ER, TRAMADOL HCL ER, XTAMPZA ER |
| Slt Opioids (Immediate Release)/Antipsychotics;Phenothiazine SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Concurrent use of opioids and antipsychotics, including phenothiazine derivatives, may result in additive CNS depression.(1) CLINICAL EFFECTS: Concurrent use of opioids and other CNS depressants, such as antipsychotics, including phenothiazine derivatives, may result in profound sedation, respiratory depression, coma, and/or death.(1) PREDISPOSING FACTORS: Concurrent use of alcohol or other CNS depressants may increase the risk of adverse effects. PATIENT MANAGEMENT: Limit prescribing opioid analgesics with CNS depressants such as antipsychotics, including phenothiazine derivatives, to patients for whom alternatives are inadequate.(1) If concurrent use is necessary, limit the dosages and duration of each drug to the minimum possible while achieving the desired clinical effect. If starting a CNS depressant (for an indication other than epilepsy) with an opioid analgesic, prescribe a lower initial dose of the CNS depressant than indicated in the absence of an opioid and titrate based upon clinical response. If an opioid analgesic is indicated in a patient already taking a CNS depressant, prescribe a lower dose of the opioid and titrate based upon clinical response.(1) Respiratory depression can occur at any time during opioid therapy, especially during therapy initiation and following dosage increases. Consider this risk when using concurrently with other agents that may cause CNS depression.(2) Monitor patients receiving concurrent therapy for unusual dizziness or lightheadedness, extreme sleepiness, slowed or difficult breathing, or unresponsiveness.(1) Discuss naloxone with all patients when prescribing or renewing an opioid analgesic or medicine to treat opioid use disorder (OUD). Consider prescribing naloxone to patients prescribed medicines to treat OUD or opioid analgesics (such as those taking CNS depressants) who are at increased risk of opioid overdose and when a patient has household members/close contacts at risk for accidental overdose.(3) DISCUSSION: A nested case-control study looked at the relationship between antipsychotic use and risk of acute respiratory failure. Current use of antipsychotics was associated with a 2.33-fold increase in risk of respiratory failure compared to no use of antipsychotics. The risk was also significantly increased in patients with recent use of antipsychotics (within the past 15-30 days, OR = 1.79) and recent past use (within 31-90 days OR = 1.41). The risk increased with higher doses and longer duration of use.(4) Between 2002 and 2014, the number of patients receiving an opioid analgesic increased 8%, from 75 million to 81 million patients, and the number of patients receiving a benzodiazepine increased 31%, from 23 million to 30 million patients. During this time, the proportion of patients receiving concurrent therapy increased 31%, from 23 million to 30 million patients.(5) From 2004 to 2011, the rate of nonmedical use-related emergency room visits involving both opioids and benzodiazepines increased from 11 to 34.2 per 100,000 and drug overdose deaths involving both opioids and benzodiazepines increased from 0.6 to 1.7 per 100,000. The proportion of prescription opioid analgesic deaths which also involved benzodiazepines increased from 18% to 31% during this time.(6) A prospective observational cohort study in North Carolina found that the rates of overdose death among patients co-dispensed opioid analgesics and benzodiazepines were 10 times higher than patients receiving opioid analgesics alone.(7) A case-cohort study of VA data from 2004-2009 found that the risk of death from overdose increased with concomitant opioid analgesics and benzodiazepines. Compared to patients with no history of benzodiazepines, patients with a history of benzodiazepine use (hazard ratio [HR] = 2.33) and patients with a current benzodiazepine prescription (HR=3.86) had an increased risk of fatal overdose.(8) A study found that opioid analgesics contributed to 77% of deaths in which benzodiazepines were determined to be a cause of death and that benzodiazepines contributed to 30% of deaths in which opioid analgesics were determined to be a cause of death. This study also found that other CNS depressants (including barbiturates, antipsychotic and neuroleptic drugs, antiepileptic and antiparkinsonian drugs, anesthetics, autonomic nervous system drugs, and muscle relaxants) were contributory to death in many cases where opioid analgesics were also implicated.(9) A study found that alcohol was involved in 18.5% of opioid analgesic abuse-related ED visits and 22.1 percent of opioid analgesic-related deaths.(10) |
APADAZ, BELBUCA, BELLADONNA-OPIUM, BENZHYDROCODONE-ACETAMINOPHEN, BUPRENORPHINE HCL, BUTORPHANOL TARTRATE, DILAUDID, DSUVIA, DURAMORPH, ENDOCET, FENTANYL CITRATE, FENTANYL CITRATE-0.9% NACL, FENTANYL CITRATE-D5W, FENTANYL CITRATE-STERILE WATER, FENTANYL CITRATE-WATER, FENTANYL-BUPIVACAINE-0.9% NACL, FENTANYL-BUPIVACAINE-NACL, FENTANYL-ROPIVACAINE-0.9% NACL, FENTANYL-ROPIVACAINE-NACL, HYDROCODONE BITARTRATE, HYDROCODONE-ACETAMINOPHEN, HYDROCODONE-IBUPROFEN, HYDROMORPHONE HCL, HYDROMORPHONE HCL-0.9% NACL, HYDROMORPHONE HCL-D5W, HYDROMORPHONE HCL-NACL, HYDROMORPHONE HCL-WATER, INFUMORPH, MITIGO, MORPHINE SULFATE, MORPHINE SULFATE-0.9% NACL, MORPHINE SULFATE-NACL, NALBUPHINE HCL, NALOCET, NUCYNTA, OLINVYK, OPIUM TINCTURE, OXYCODONE HCL, OXYCODONE HYDROCHLORIDE, OXYCODONE-ACETAMINOPHEN, OXYMORPHONE HCL, PENTAZOCINE-NALOXONE HCL, PERCOCET, PRIMLEV, PROLATE, REMIFENTANIL HCL, ROXICODONE, ROXYBOND, SUFENTANIL CITRATE, ULTIVA |
| Trazodone (Less Than 100 mg)/QT Prolonging Agents SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Concurrent use of trazodone with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1,2) CLINICAL EFFECTS: The use of trazodone in patients maintained on agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1,2) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: The US manufacturer of trazodone states that concurrent use with agents known to prolong the QT interval should be avoided.(1) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Trazodone has been reported to prolong the QT interval.(1) A thorough QT study in 20 subjects evaluated the effects of trazodone at doses of 20 mg, 60 mg and 140 mg. There was no evidence of QTc prolongation at the lowest trazodone dose of 20mg (mean effect on QTc of 4.5 ms 95% CI 3.7-5.3 ms), but at 60 mg and 140 mg, there was a significant effect that exceeds the E14 FDA Guidelines threshold of prolonging the QT/QTc interval by more than 5 ms. The study found a dose-dependent effect on QTc prolongation starting at 60 mg with a mean effect on QTc of 12.3 ms (95% CI 11-13.6 ms) and increasing with a 140 mg dose to a mean effect on QTc of 19.8 ms (95% CI 17.6-22.1).(3) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(4) |
TRAZODONE HCL |
| Gilteritinib/QT Prolonging Agents SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Concurrent use of gilteritinib with agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of gilteritinib with agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(1) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, and/or renal/hepatic dysfunction).(1) PATIENT MANAGEMENT: When concurrent therapy cannot be avoided, obtain ECGs and electrolyte values (serum calcium, magnesium, and potassium) prior to the start of treatment, after initiation of any drug known to prolong the QT interval, and periodically monitor during therapy. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. Prior to initiation of therapy with gilteritinib, obtain baseline ECG and on days 8 and 15 of cycle 1, and prior to the start of the next two subsequent cycles. If QTc prolongation develops: ---Monitor and supplement electrolytes as clinically indicated ---Review and adjust concomitant QT prolonging medications For a QTc interval greater than 500 msec: ---Interrupt gilteritinib therapy ---Resume gilteritinib therapy at 80 mg when the QTc interval returns to within 30 msec of baseline or <= 480 msec. For QTc interval increased by > 30 msec on ECG on Day 8 of cycle 1: ---Confirm with ECG on Day 9 ---If confirmed, consider dose reduction to 80 mg.(2) DISCUSSION: In the gilteritinib clinical trial, 1.4% of patients developed a QTc interval greater than 500 msec and 7% of patients had an increase QTc greater than 60 msec.(2) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(3) |
XOSPATA |
| Meperidine (IR)/Selected Antipsychotics; Phenothiazines SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Concurrent use of opioids such as meperidine and antipsychotics, including phenothiazine derivatives, may result in additive CNS depression.(1) CLINICAL EFFECTS: Concurrent use of opioids such as meperidine and other CNS depressants, such as antipsychotics, including phenothiazine derivatives, may result in profound sedation, respiratory depression, coma, and/or death.(1) PREDISPOSING FACTORS: Concurrent use of alcohol or other CNS depressants may increase the risk of adverse effects. PATIENT MANAGEMENT: Limit prescribing opioid analgesics such as meperidine with CNS depressants such as antipsychotics, including phenothiazine derivatives, to patients for whom alternatives are inadequate.(1) If concurrent use is necessary, limit the dosages and duration of each drug to the minimum possible while achieving the desired clinical effect. If starting a CNS depressant (for an indication other than epilepsy) with an opioid analgesic, prescribe a lower initial dose of the CNS depressant than indicated in the absence of an opioid and titrate based upon clinical response. If an opioid analgesic is indicated in a patient already taking a CNS depressant, prescribe a lower dose of the opioid and titrate based upon clinical response.(1) Respiratory depression can occur at any time during opioid therapy, especially during therapy initiation and following dosage increases. Consider this risk when using concurrently with other agents that may cause CNS depression.(2) Monitor patients receiving concurrent therapy for unusual dizziness or lightheadedness, extreme sleepiness, slowed or difficult breathing, or unresponsiveness.(1) Discuss naloxone with all patients when prescribing or renewing an opioid analgesic or medicine to treat opioid use disorder (OUD). Consider prescribing naloxone to patients prescribed medicines to treat OUD or opioid analgesics (such as those taking CNS depressants) who are at increased risk of opioid overdose and when a patient has household members/close contacts at risk for accidental overdose.(3) DISCUSSION: A nested case-control study looked at the relationship between antipsychotic use and risk of acute respiratory failure. Current use of antipsychotics was associated with a 2.33-fold increase in risk of respiratory failure compared to no use of antipsychotics. The risk was also significantly increased in patients with recent use of antipsychotics (within the past 15-30 days, OR = 1.79) and recent past use (within 31-90 days OR = 1.41). The risk increased with higher doses and longer duration of use.(4) Between 2002 and 2014, the number of patients receiving an opioid analgesic increased 8%, from 75 million to 81 million patients, and the number of patients receiving a benzodiazepine increased 31%, from 23 million to 30 million patients. During this time, the proportion of patients receiving concurrent therapy increased 31%, from 23 million to 30 million patients.(5) From 2004 to 2011, the rate of nonmedical use-related emergency room visits involving both opioids and benzodiazepines increased from 11 to 34.2 per 100,000 and drug overdose deaths involving both opioids and benzodiazepines increased from 0.6 to 1.7 per 100,000. The proportion of prescription opioid analgesic deaths which also involved benzodiazepines increased from 18% to 31% during this time.(6) A prospective observational cohort study in North Carolina found that the rates of overdose death among patients co-dispensed opioid analgesics and benzodiazepines were 10 times higher than patients receiving opioid analgesics alone.(7) A case-cohort study of VA data from 2004-2009 found that the risk of death from overdose increased with concomitant opioid analgesics and benzodiazepines. Compared to patients with no history of benzodiazepines, patients with a history of benzodiazepine use (hazard ratio [HR] = 2.33) and patients with a current benzodiazepine prescription (HR=3.86) had an increased risk of fatal overdose.(8) A study found that opioid analgesics contributed to 77% of deaths in which benzodiazepines were determined to be a cause of death and that benzodiazepines contributed to 30% of deaths in which opioid analgesics were determined to be a cause of death. This study also found that other CNS depressants (including barbiturates, antipsychotic and neuroleptic drugs, antiepileptic and antiparkinsonian drugs, anesthetics, autonomic nervous system drugs, and muscle relaxants) were contributory to death in many cases where opioid analgesics were also implicated.(9) A study found that alcohol was involved in 18.5% of opioid analgesic abuse-related ED visits and 22.1 percent of opioid analgesic-related deaths.(10) |
DEMEROL, MEPERIDINE HCL, MEPERIDINE HCL-0.9% NACL |
| Codeine; Levorphanol (IR)/Slt Antipsychotics; Phenothiazines SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Concurrent use of opioids such as codeine and levorphanol and antipsychotics, including phenothiazine derivatives, may result in additive CNS depression.(1) CLINICAL EFFECTS: Concurrent use of opioids such as codeine and levorphanol and other CNS depressants, such as antipsychotics, including phenothiazine derivatives, may result in profound sedation, respiratory depression, coma, and/or death.(1) PREDISPOSING FACTORS: Concurrent use of alcohol or other CNS depressants may increase the risk of adverse effects. PATIENT MANAGEMENT: Limit prescribing opioid analgesics such as codeine and levorphanol with CNS depressants such as antipsychotics, including phenothiazine derivatives, to patients for whom alternatives are inadequate.(1) If concurrent use is necessary, limit the dosages and duration of each drug to the minimum possible while achieving the desired clinical effect. If starting a CNS depressant (for an indication other than epilepsy) with an opioid analgesic, prescribe a lower initial dose of the CNS depressant than indicated in the absence of an opioid and titrate based upon clinical response. If an opioid analgesic is indicated in a patient already taking a CNS depressant, prescribe a lower dose of the opioid and titrate based upon clinical response.(1) Respiratory depression can occur at any time during opioid therapy, especially during therapy initiation and following dosage increases. Consider this risk when using concurrently with other agents that may cause CNS depression.(2) Monitor patients receiving concurrent therapy for unusual dizziness or lightheadedness, extreme sleepiness, slowed or difficult breathing, or unresponsiveness.(1) Discuss naloxone with all patients when prescribing or renewing an opioid analgesic or medicine to treat opioid use disorder (OUD). Consider prescribing naloxone to patients prescribed medicines to treat OUD or opioid analgesics (such as those taking CNS depressants) who are at increased risk of opioid overdose and when a patient has household members/close contacts at risk for accidental overdose.(3) DISCUSSION: A nested case-control study looked at the relationship between antipsychotic use and risk of acute respiratory failure. Current use of antipsychotics was associated with a 2.33-fold increase in risk of respiratory failure compared to no use of antipsychotics. The risk was also significantly increased in patients with recent use of antipsychotics (within the past 15-30 days, OR = 1.79) and recent past use (within 31-90 days OR = 1.41). The risk increased with higher doses and longer duration of use.(4) Between 2002 and 2014, the number of patients receiving an opioid analgesic increased 8%, from 75 million to 81 million patients, and the number of patients receiving a benzodiazepine increased 31%, from 23 million to 30 million patients. During this time, the proportion of patients receiving concurrent therapy increased 31%, from 23 million to 30 million patients.(5) From 2004 to 2011, the rate of nonmedical use-related emergency room visits involving both opioids and benzodiazepines increased from 11 to 34.2 per 100,000 and drug overdose deaths involving both opioids and benzodiazepines increased from 0.6 to 1.7 per 100,000. The proportion of prescription opioid analgesic deaths which also involved benzodiazepines increased from 18% to 31% during this time.(6) A prospective observational cohort study in North Carolina found that the rates of overdose death among patients co-dispensed opioid analgesics and benzodiazepines were 10 times higher than patients receiving opioid analgesics alone.(7) A case-cohort study of VA data from 2004-2009 found that the risk of death from overdose increased with concomitant opioid analgesics and benzodiazepines. Compared to patients with no history of benzodiazepines, patients with a history of benzodiazepine use (hazard ratio [HR] = 2.33) and patients with a current benzodiazepine prescription (HR=3.86) had an increased risk of fatal overdose.(8) A study found that opioid analgesics contributed to 77% of deaths in which benzodiazepines were determined to be a cause of death and that benzodiazepines contributed to 30% of deaths in which opioid analgesics were determined to be a cause of death. This study also found that other CNS depressants (including barbiturates, antipsychotic and neuroleptic drugs, antiepileptic and antiparkinsonian drugs, anesthetics, autonomic nervous system drugs, and muscle relaxants) were contributory to death in many cases where opioid analgesics were also implicated.(9) A study found that alcohol was involved in 18.5% of opioid analgesic abuse-related ED visits and 22.1 percent of opioid analgesic-related deaths.(10) |
ACETAMIN-CAFF-DIHYDROCODEINE, ACETAMINOPHEN-CODEINE, ASA-BUTALB-CAFFEINE-CODEINE, ASCOMP WITH CODEINE, BUTALB-ACETAMINOPH-CAFF-CODEIN, CARISOPRODOL-ASPIRIN-CODEINE, CODEINE PHOSPHATE, CODEINE SULFATE, DIHYDROCODEINE BITARTRATE, FIORICET WITH CODEINE, HYDROCODONE BITARTRATE, LEVORPHANOL TARTRATE, TREZIX |
| Tramadol (IR)/Selected Antipsychotics; Phenothiazines SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Concurrent use of opioids such as tramadol and antipsychotics, including phenothiazine derivatives, may result in additive CNS depression.(1) CLINICAL EFFECTS: Concurrent use of opioids such as tramadol and other CNS depressants, such as antipsychotics, including phenothiazine derivatives, may result in profound sedation, respiratory depression, coma, and/or death.(1) PREDISPOSING FACTORS: Concurrent use of alcohol or other CNS depressants may increase the risk of adverse effects. PATIENT MANAGEMENT: Limit prescribing opioid analgesics such as tramadol with CNS depressants such as antipsychotics, including phenothiazine derivatives, to patients for whom alternatives are inadequate.(1) If concurrent use is necessary, limit the dosages and duration of each drug to the minimum possible while achieving the desired clinical effect. If starting a CNS depressant (for an indication other than epilepsy) with an opioid analgesic, prescribe a lower initial dose of the CNS depressant than indicated in the absence of an opioid and titrate based upon clinical response. If an opioid analgesic is indicated in a patient already taking a CNS depressant, prescribe a lower dose of the opioid and titrate based upon clinical response.(1) Respiratory depression can occur at any time during opioid therapy, especially during therapy initiation and following dosage increases. Consider this risk when using concurrently with other agents that may cause CNS depression.(2) Monitor patients receiving concurrent therapy for unusual dizziness or lightheadedness, extreme sleepiness, slowed or difficult breathing, or unresponsiveness.(1) Discuss naloxone with all patients when prescribing or renewing an opioid analgesic or medicine to treat opioid use disorder (OUD). Consider prescribing naloxone to patients prescribed medicines to treat OUD or opioid analgesics (such as those taking CNS depressants) who are at increased risk of opioid overdose and when a patient has household members/close contacts at risk for accidental overdose.(3) DISCUSSION: A nested case-control study looked at the relationship between antipsychotic use and risk of acute respiratory failure. Current use of antipsychotics was associated with a 2.33-fold increase in risk of respiratory failure compared to no use of antipsychotics. The risk was also significantly increased in patients with recent use of antipsychotics (within the past 15-30 days, OR = 1.79) and recent past use (within 31-90 days OR = 1.41). The risk increased with higher doses and longer duration of use.(4) Between 2002 and 2014, the number of patients receiving an opioid analgesic increased 8%, from 75 million to 81 million patients, and the number of patients receiving a benzodiazepine increased 31%, from 23 million to 30 million patients. During this time, the proportion of patients receiving concurrent therapy increased 31%, from 23 million to 30 million patients.(5) From 2004 to 2011, the rate of nonmedical use-related emergency room visits involving both opioids and benzodiazepines increased from 11 to 34.2 per 100,000 and drug overdose deaths involving both opioids and benzodiazepines increased from 0.6 to 1.7 per 100,000. The proportion of prescription opioid analgesic deaths which also involved benzodiazepines increased from 18% to 31% during this time.(6) A prospective observational cohort study in North Carolina found that the rates of overdose death among patients co-dispensed opioid analgesics and benzodiazepines were 10 times higher than patients receiving opioid analgesics alone.(7) A case-cohort study of VA data from 2004-2009 found that the risk of death from overdose increased with concomitant opioid analgesics and benzodiazepines. Compared to patients with no history of benzodiazepines, patients with a history of benzodiazepine use (hazard ratio [HR] = 2.33) and patients with a current benzodiazepine prescription (HR=3.86) had an increased risk of fatal overdose.(8) A study found that opioid analgesics contributed to 77% of deaths in which benzodiazepines were determined to be a cause of death and that benzodiazepines contributed to 30% of deaths in which opioid analgesics were determined to be a cause of death. This study also found that other CNS depressants (including barbiturates, antipsychotic and neuroleptic drugs, antiepileptic and antiparkinsonian drugs, anesthetics, autonomic nervous system drugs, and muscle relaxants) were contributory to death in many cases where opioid analgesics were also implicated.(9) A study found that alcohol was involved in 18.5% of opioid analgesic abuse-related ED visits and 22.1 percent of opioid analgesic-related deaths.(10) |
QDOLO, TRAMADOL HCL, TRAMADOL HCL-ACETAMINOPHEN |
| Pitolisant/QT Prolonging Agents SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Concurrent use of pitolisant with agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of pitolisant with agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: Patients who are CYP2D6 poor metabolizers or on concurrent use with CYP2D6 inhibitors are at increased risk for higher systemic exposure to pitolisant and may be at increased risk of QT prolongation.(1) The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: When concurrent therapy cannot be avoided, obtain ECGs and electrolyte values (serum calcium, magnesium, and potassium) prior to the start of treatment, after initiation of any drug known to prolong the QT interval, and periodically monitor during therapy. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting.(2) DISCUSSION: In two dedicated QT prolongation studies, supra-therapeutic doses of pitolisant at 3-6 times the therapeutic dose (108-216 mg) were seen to cause mild to moderate QTc prolongation (10-13 ms). A study in patients who were CYP2D6 poor metabolizers had higher systemic exposure up to 3-fold compared to CYP2D6 extensive metabolizers.(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(3) |
WAKIX |
| Selected Opioids for MAT/Selected Antipsychotics SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Concurrent use of buprenorphine or diacetylmorphine and antipsychotics may result in additive CNS depression.(1-3) CLINICAL EFFECTS: Concurrent use of buprenorphine or diacetylmorphine and antipsychotics may result in profound sedation, respiratory depression, coma, and/or death.(1-3) PREDISPOSING FACTORS: Concurrent use of alcohol or other CNS depressants may increase the risk of adverse effects. PATIENT MANAGEMENT: Medication assisted treatment (MAT) with buprenorphine or diacetylmorphine is not contraindicated in patients taking CNS depressants, such as antipsychotics; however, gradual tapering or decreasing to the lowest effective dose of the antipsychotic may be appropriate. Ensure that other health care providers prescribing other CNS depressants are aware of the patient's buprenorphine or diacetylmorphine treatment.(2) Respiratory depression can occur at any time during opioid therapy, especially during therapy initiation and following dosage increases. Consider this risk when using concurrently with other agents that may cause CNS depression.(4) Monitor patients receiving concurrent therapy for unusual dizziness or lightheadedness, extreme sleepiness, slowed or difficult breathing, or unresponsiveness.(1) Discuss naloxone with all patients when prescribing or renewing an opioid analgesic or medicine to treat opioid use disorder (OUD). Consider prescribing naloxone to patients prescribed medicines to treat OUD or opioid analgesics (such as those taking CNS depressants) who are at increased risk of opioid overdose and when a patient has household members/close contacts at risk for accidental overdose.(5) DISCUSSION: A nested case-control study looked at the relationship between antipsychotic use and risk of acute respiratory failure. Current use of antipsychotics was associated with a 2.33-fold increase in risk of respiratory failure compared to no use of antipsychotics. The risk was also significantly increased in patients with recent use of antipsychotics (within the past 15-30 days, OR = 1.79) and recent past use (within 31-90 days OR = 1.41). The risk increased with higher doses and longer duration of use.(6) Between 2002 and 2014, the number of patients receiving an opioid analgesic increased 8%, from 75 million to 81 million patients, and the number of patients receiving a benzodiazepine increased 31%, from 23 million to 30 million patients. During this time, the proportion of patients receiving concurrent therapy increased 31%, from 23 million to 30 million patients.(7) From 2004 to 2011, the rate of nonmedical use-related emergency room visits involving both opioids and benzodiazepines increased from 11 to 34.2 per 100,000 and drug overdose deaths involving both opioids and benzodiazepines increased from 0.6 to 1.7 per 100,000. The proportion of prescription opioid analgesic deaths which also involved benzodiazepines increased from 18% to 31% during this time.(8) A prospective observational cohort study in North Carolina found that the rates of overdose death among patients co-dispensed opioid analgesics and benzodiazepines were 10 times higher than patients receiving opioid analgesics alone.(9) A case-cohort study of VA data from 2004-2009 found that the risk of death from overdose increased with concomitant opioid analgesics and benzodiazepines. Compared to patients with no history of benzodiazepines, patients with a history of benzodiazepine use (hazard ratio [HR] = 2.33) and patients with a current benzodiazepine prescription (HR=3.86) had an increased risk of fatal overdose.(10) A study found that opioid analgesics contributed to 77% of deaths in which benzodiazepines were determined to be a cause of death and that benzodiazepines contributed to 30% of deaths in which opioid analgesics were determined to be a cause of death. This study also found that other CNS depressants (including barbiturates, antipsychotic and neuroleptic drugs, antiepileptic and antiparkinsonian drugs, anesthetics, autonomic nervous system drugs, and muscle relaxants) were contributory to death in many cases where opioid analgesics were also implicated.(11) A study found that alcohol was involved in 18.5% of opioid analgesic abuse-related ED visits and 22.1 percent of opioid analgesic-related deaths.(12) Selected antipsychotics linked include: amsulpride, chlorpromazine, chlorprothixene, clozapine, droperidol, haloperidol, iloperidone, mesoridazine, paliperidone, pimavanserin, pimozide, pipamperone, promethazine, quetiapine, sertindole, sulpiride, sultopride, thioridazine, ziprasidone, and zuclopenthixol. |
BRIXADI, BUPRENORPHINE HCL, BUPRENORPHINE-NALOXONE, SUBLOCADE, SUBOXONE, ZUBSOLV |
| Amisulpride/QT Prolonging Agents SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Amisulpride has been shown to prolong the QT interval. Concurrent use with QT prolonging agents may result in additive effects on the QT interval.(1) CLINICAL EFFECTS: The concurrent use of amisulpride with agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: Use caution when using amisulpride concurrently with other agents that can prolong the QT interval. Amisulpride may cause a dose and concentration dependent increase in the QTc interval. When concurrent therapy cannot be avoided, obtain ECGs and electrolyte values (serum calcium, magnesium, and potassium) prior to the start of treatment, after initiation of any drug known to prolong the QT interval, and periodically monitor during therapy. ECG monitoring is recommended in patients with pre-existing arrhythmias or cardiac conduction disorders; electrolyte abnormalities; congestive heart failure; or in patients taking medications or with other medical conditions known to prolong the QT interval. Correct any electrolyte abnormalities.(1) Instruct patients to report any irregular heartbeat, dizziness, or fainting.(2) DISCUSSION: QT prolongation and torsades de pointes have been reported with amisulpride. In a study in 40 patients with post operative nausea and vomiting, amisulpride increased baseline QTcF by 5 msec after a 2-minute intravenous infusion of 5 mg and by 23.4 msec after an 8-minute intravenous infusion of 40 mg. Based on an exposure-response relationship, it is expected that a 10 mg intravenous infusion over 1 minute may increase the QTcF by 13.4 msec.(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(3) |
BARHEMSYS |
| Osilodrostat/QT Prolonging Agents SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Osilodrostat has been shown to prolong the QT interval. Concurrent use with QT prolonging agents may result in additive effects on the QT interval.(1) CLINICAL EFFECTS: The concurrent use of osilodrostat with agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: Use caution when using osilodrostat concurrently with other agents that can prolong the QT interval and consider more frequent ECG monitoring. A dose-dependent QT interval prolongation was noted in clinical studies. Prior to initiating therapy with osilodrostat, obtain a baseline ECG and monitor for QTc interval changes thereafter. Consider temporary discontinuation of therapy if the QTc interval increases > 480 msec. When concurrent therapy cannot be avoided, obtain ECGs and electrolyte values (serum calcium, magnesium, and potassium) prior to the start of treatment, after initiation of any drug known to prolong the QT interval, and periodically monitor during therapy. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting.(2) DISCUSSION: QTc prolongation has been reported with osilodrostat. In a thorough QT study in 86 healthy patients, osilodrostat increased baseline QTcF by 1.73 msec at a 10 mg dose and 25.38 msec at a 150 mg dose (up to 2.5 times the maximum recommended dosage). The predicted mean placebo-corrected QTcF at the highest recommended dose in clinical practice (30 mg twice daily) was estimated as 5.3 msec.(1) In a clinical study, five patients (4%) were reported to have an event of QT prolongation, three patients (2%) had a QTcF increase of > 60 msec from baseline, and 18 patients (13%) had a new QTcF value of > 450 msec.(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(3) |
ISTURISA |
| Zonisamide/Anticholinergics SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Zonisamide can cause decreased sweating and elevated body temperature. Agents with anticholinergic activity can predispose patients to heat-related disorders.(1-2) CLINICAL EFFECTS: Concurrent use of zonisamide with agents with anticholinergic activity may increase the incidence of oligohidrosis and hyperthermia, especially in pediatric or adolescent patients.(1-2) Overheating and dehydration can lead to brain damage and death. PREDISPOSING FACTORS: Pediatric and adolescent patients and patients with dehydration may be more likely to experience heat-related disorders.(1) PATIENT MANAGEMENT: The UK and US manufacturers of zonisamide state that caution should be used in adults when zonisamide is prescribed with other medicinal products that predispose to heat-related disorders, such as agents with anticholinergic activity.(1-2) Pediatric and adolescent patients must not take anticholinergic agents (e.g. clomipramine, hydroxyzine, diphenhydramine, haloperidol, imipramine, and oxybutynin) concurrently with zonisamide.(1) Monitor for signs and symptoms of heat stroke: skin feels very hot with little or no sweating, confusion, muscle cramps, rapid heartbeat, or rapid breathing. Monitor for signs and symptoms of dehydration: dry mouth, urinating less than usual, dark-colored urine, dry skin, feeling tired, dizziness, or irritability. If signs or symptoms of dehydration, oligohidrosis, or elevated body temperature occur, discontinuation of zonisamide should be considered. DISCUSSION: Case reports of decreased sweating and elevated temperature have been reported, especially in pediatric patients. Some cases resulted in heat stroke that required hospital treatment and resulted in death.(1) |
ZONEGRAN, ZONISADE, ZONISAMIDE |
| Topiramate/Anticholinergics SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Topiramate can cause decreased sweating and elevated body temperature. Agents with anticholinergic activity can predispose patients to heat-related disorders.(1-2) CLINICAL EFFECTS: Concurrent use of topiramate with agents with anticholinergic activity may increase the incidence of oligohidrosis and hyperthermia, especially in pediatric or adolescent patients.(1-2) Overheating and dehydration can lead to brain damage and death. PREDISPOSING FACTORS: Pediatric and adolescent patients and patients with dehydration may be more likely to experience heat-related disorders.(1) PATIENT MANAGEMENT: The manufacturer of topiramate states that caution should be used when topiramate is prescribed with other medicinal products that predispose to heat-related disorders, such as agents with anticholinergic activity (e.g. clomipramine, hydroxyzine, diphenhydramine, haloperidol, imipramine, and oxybutynin) concurrently with zonisamide.(1) Monitor for signs and symptoms of heat stroke: skin feels very hot with little or no sweating, confusion, muscle cramps, rapid heartbeat, or rapid breathing. Monitor for signs and symptoms of dehydration: dry mouth, urinating less than usual, dark-colored urine, dry skin, feeling tired, dizziness, or irritability. If signs or symptoms of dehydration, oligohidrosis, or elevated body temperature occur, discontinuation of zonisamide should be considered. DISCUSSION: Case reports of decreased sweating and elevated temperature have been reported, especially in pediatric patients. Some cases resulted in heat stroke that required hospital treatment.(1) A 64-year old woman developed non-exertional hyperthemia while taking multiple psychiatric medications with topiramate.(2) |
EPRONTIA, QSYMIA, TOPAMAX, TOPIRAMATE, TOPIRAMATE ER, TOPIRAMATE ER SPRINKLE, TROKENDI XR |
| Haloperidol/Barbiturates SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Strong CYP3A4 inducers may increase the metabolism of haloperidol. The concurrent administration of haloperidol and barbiturates may result in additive CNS depressant effects.(1) CLINICAL EFFECTS: Concurrent use may result in potentiation of CNS depression, which may result in hypotension, increased sedation, and respiratory depression.(1) Some barbiturates may reduce the effectiveness of haloperidol.(1) PREDISPOSING FACTORS: Induction effects may be more likely with regular use of the inducer for longer than 1-2 weeks. PATIENT MANAGEMENT: Respiration and blood pressure should be closely monitored in patients receiving concurrent barbiturate and haloperidol therapy. The dosage of the barbiturate may need to be adjusted in patients receiving barbiturates for indications other than anticonvulsant use. Carefully monitor clinical response in patients maintained on haloperidol when initiating or discontinuing inducers of CYP3A4 such as barbiturates. The dose of haloperidol may need to be adjusted.(1) DISCUSSION: A nested case-control study looked at the relationship between antipsychotic use and risk of acute respiratory failure. Current use of antipsychotics was associated with a 2.33-fold increase in risk of respiratory failure compared to no use of antipsychotics. The risk was also significantly increased in patients with recent use of antipsychotics (within the past 15-30 days, OR = 1.79) and recent past use (within 31-90 days OR = 1.41). The risk increased with higher doses and longer duration of use.(2) In a retrospective review of 231 schizophrenic patients, patients receiving concurrent carbamazepine or phenobarbital (strong CYP3A4 inducers) had haloperidol levels that were 37% and 22% lower, respectively, than patients taking haloperidol without these agents.(3) In a study in schizophrenic patients, the addition of rifampin (a strong CYP3A4 inducer) in 12 patients resulted in decreases in haloperidol levels by 37%, 58.7%, and 70% by Day 3, Day 7, and Day 28, respectively, of concurrent therapy. Mean scores on the Brief Psychiatric Rating Scale decreased from baseline. Discontinuation of rifampin from concurrent therapy in 5 patients increased haloperidol levels by 140.7%, 228.7%, and 329% of baseline by Day 3, Day 7, and Day 28, respectively, after rifampin discontinuation.(1,4) In a study in 7 schizophrenic patients, rifampin decreased the half-life of haloperidol by 48%.(5) |
ASA-BUTALB-CAFFEINE-CODEINE, ASCOMP WITH CODEINE, BUTALB-ACETAMINOPH-CAFF-CODEIN, BUTALBITAL, BUTALBITAL-ACETAMINOPHEN, BUTALBITAL-ACETAMINOPHEN-CAFFE, BUTALBITAL-ASPIRIN-CAFFEINE, DONNATAL, FIORICET, FIORICET WITH CODEINE, MYSOLINE, PENTOBARBITAL SODIUM, PHENOBARBITAL, PHENOBARBITAL SODIUM, PHENOBARBITAL-BELLADONNA, PHENOBARBITAL-HYOSC-ATROP-SCOP, PHENOHYTRO, PRIMIDONE, SEZABY, TENCON |
| Haloperidol/Selected Strong CYP3A4 Inducers SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Strong CYP3A4 inducers may increase the metabolic clearance of haloperidol.(1) CLINICAL EFFECTS: Coadministration with a strong CYP3A4 inducer may result in decreased levels and effectiveness of haloperidol.(1) PREDISPOSING FACTORS: Induction effects may be more likely with regular use of the inducer for longer than 1-2 weeks. PATIENT MANAGEMENT: Monitor clinical response in patients maintained on haloperidol when initiating or discontinuing strong CYP3A4 inducers. The dosage of haloperidol may need to be adjusted.(1) DISCUSSION: In a study in 11 schizophrenic patients, the addition of carbamazepine resulted in a dose related decrease in haloperidol levels. Haloperidol levels were decreased by 2%, 61%, and 85%, respectively, from baseline following the addition and increase of carbamazepine at 100 mg/day, 300 mg/day, and 600 mg/day.(1,2) In a study in 27 patients with schizophrenia or schizoaffective disorder, the use of haloperidol with carbamazepine was associated with lower haloperidol levels and worse clinical outcomes than the use of haloperidol alone.(3) In a study in schizophrenic patients, haloperidol levels were significantly decreased in patients receiving concurrent carbamazepine.(4) In a study in 7 patients, haloperidol levels fell 60% following the addition of carbamazepine to therapy. Haloperidol levels were undetectable in 2 subjects, whose symptoms worsened.(5) In a study in 23 patients, the addition of carbamazepine to haloperidol resulted in improvement in symptoms.(6) In a retrospective review of 231 schizophrenic patients, patients receiving concurrent carbamazepine or phenobarbital had haloperidol levels that were 37% and 22% lower, respectively, than patients taking haloperidol without these agents.(7) In a study in 6 schizophrenic patients, switching carbamazepine to oxcarbazepine resulted in increased in haloperidol levels by 50% to 200% after 2-4 weeks of therapy.(8) In a study in schizophrenic patients, carbamazepine decreased haloperidol levels by 50%. One subject developed worsening of symptoms, while two improved.(9) There are also case reports documenting decreased haloperidol levels and effectiveness with concurrent carbamazepine.(10-14) In a study in schizophrenic patients, the addition of rifampin in 12 patients resulted in decreases in haloperidol levels by 37%, 58.7%, and 70% by Day 3, Day 7, and Day 28, respectively, of concurrent therapy. Mean scores on the Brief Psychiatric Rating Scale decreased from baseline. Discontinuation of rifampin from concurrent therapy in 5 patients increased haloperidol levels by 140.7%, 228.7%, and 329% of baseline by Day 3, Day 7, and Day 28, respectively, after rifampin discontinuation.(1,15) In a study in 7 schizophrenic patients, rifampin decreased the half-life of haloperidol by 48%.(16) Strong CYP3A4 inducers linked to this monograph are: carbamazepine, enzalutamide, fosphenytoin, lumacaftor, mitotane, phenytoin, rifampin, rifapentine and St. John's Wort.(17,18) |
CARBAMAZEPINE, CARBAMAZEPINE ER, CARBATROL, CEREBYX, DILANTIN, DILANTIN-125, EPITOL, EQUETRO, FOSPHENYTOIN SODIUM, LYSODREN, MITOTANE, ORKAMBI, PHENYTEK, PHENYTOIN, PHENYTOIN SODIUM, PHENYTOIN SODIUM EXTENDED, PRIFTIN, RIFADIN, RIFAMPIN, TEGRETOL, TEGRETOL XR, XTANDI |
| Galantamine/QT Prolonging Agents SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Galantamine may reduce heart rate by increasing acetylcholine in the heart and increasing vagal tone. Bradycardia has been associated with increased risk of QTc interval prolongation.(1) Concurrent use of galantamine with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(2) CLINICAL EFFECTS: The use of galantamine in patients maintained on agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(2) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, advanced age or when receiving concomitant treatment with an inhibitor of CYP3A4.(3) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(3) PATIENT MANAGEMENT: The UK manufacturer of galantamine states that it should be used with caution in patients treated with drugs that affect the QTc interval.(2) If concurrent therapy is warranted, monitor ECG more frequently and consider obtaining serum calcium, magnesium, and potassium levels at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Therapeutic doses of galantamine have been reported to cause QTc prolongation in patients.(2) An 85 year old male with dementia was restarted on galantamine 8 mg daily after a 2-week treatment interruption due to a syncopal episode that occurred 3 months previously. During his prior syncopal episode, he was hypotensive and bradycardic, but QTc interval was normal. After restarting galantamine, he was found to be hypotension and bradycardiac again, and QTc interval was significantly prolonged to 503 msec, over 60 msec longer than when he was off galantamine. Galantamine was discontinued and his QTc interval returned to baseline.(4) A 47 year old schizophrenic male experienced prolongation of the QTc interval to 518 msec after galantamine was increased from 8 mg daily to 12 mg daily. Although he was also on quetiapine and metoprolol, he had been stable on his other medications. His QTc interval normalized after galantamine was stopped.(5) The European pharmacovigilance (Eudravigilance) database contains 14 reports of torsades de pointe in patients on galantamine as of October 2019.(1) A pharmacovigilance study based on the FDA Adverse Event Reporting System (FAERS) database found that, of a total of 33,626 cases of TdP/QT prolongation reported between January 2004 and September 2022, 54 cases occurred in patients on galantamine. The disproportionality analysis found a ROR = 5.12, 95% CI (3.92,6.68) and a PRR = 5.11, chi-square = 175.44.(6) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(7) |
GALANTAMINE ER, GALANTAMINE HBR, GALANTAMINE HYDROBROMIDE, ZUNVEYL |
| Haloperidol/Apalutamide SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Apalutamide, a strong CYP3A4 inducer, may increase the metabolic clearance of haloperidol.(1-3) CLINICAL EFFECTS: Coadministration with apalutamide, a strong CYP3A4 inducer, may result in decreased levels and effectiveness of haloperidol. PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: Monitor clinical response in patients maintained on haloperidol when initiating or discontinuing strong CYP3A4 inducers. The dosage of haloperidol may need to be adjusted.(1) DISCUSSION: In a study in 11 schizophrenic patients, the addition of carbamazepine resulted in a dose related decrease in haloperidol levels. Haloperidol levels were decreased by 2%, 61%, and 85%, respectively, from baseline following the addition and increase of carbamazepine at 100 mg/day, 300 mg/day, and 600 mg/day.(1,4) In a study in 27 patients with schizophrenia or schizoaffective disorder, the use of haloperidol with carbamazepine was associated with lower haloperidol levels and worse clinical outcomes than the use of haloperidol alone.(5) In a study in schizophrenic patients, haloperidol levels were significantly decreased in patients receiving concurrent carbamazepine.(6) In a study in 7 patients, haloperidol levels fell 60% following the addition of carbamazepine to therapy. Haloperidol levels were undetectable in 2 subjects, whose symptoms worsened.(7) In a study in 23 patients, the addition of carbamazepine to haloperidol resulted in improvement in symptoms.(8) In a retrospective review of 231 schizophrenic patients, patients receiving concurrent carbamazepine or phenobarbital had haloperidol levels that were 37% and 22% lower, respectively, than patients taking haloperidol without these agents.(9) In a study in 6 schizophrenic patients, switching carbamazepine to oxcarbazepine resulted in increased in haloperidol levels by 50% to 200% after 2-4 weeks of therapy.(10) In a study in schizophrenic patients, carbamazepine decreased haloperidol levels by 50%. One subject developed worsening of symptoms, while two improved.(11) There are also case reports documenting decreased haloperidol levels and effectiveness with concurrent carbamazepine.(12-16) In a study in schizophrenic patients, the addition of rifampin in 12 patients resulted in decreases in haloperidol levels by 37%, 58.7%, and 70% by Day 3, Day 7, and Day 28, respectively, of concurrent therapy. Mean scores on the Brief Psychiatric Rating Scale decreased from baseline. Discontinuation of rifampin from concurrent therapy in 5 patients increased haloperidol levels by 140.7%, 228.7%, and 329% of baseline by Day 3, Day 7, and Day 28, respectively, after rifampin discontinuation.(1,17) In a study in 7 schizophrenic patients, rifampin decreased the half-life of haloperidol by 48%.(18) |
ERLEADA |
| Siponimod/QT Prolonging Agents SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Siponimod is a sphingosine-1-phosphate (S1P) receptor modulator. Initiation of siponimod has a negative chronotropic effect. Siponimod blocks the capacity of lymphocytes to egress from lymph nodes, reducing the number of lymphocytes in peripheral blood. The mechanism by which siponimod exerts therapeutic effects in multiple sclerosis is unknown, but may involve reduction of lymphocyte migration into the central nervous system.(1,2) CLINICAL EFFECTS: The heart rate lowering effect of siponimod starts within an hour, and the Day 1 decline is maximal at approximately 3-4 hours. This leads to a mean decrease in heart rate of 5-6 beats per minute after the first dose. The first dose has also been associated with heart block. With continued up-titration, further heart rate decreases are seen on subsequent days, with maximal decrease from Day 1-baseline reached on Day 5-6. Symptomatic bradycardia has been observed. Bradycardia may be associated with an increase in the QTc interval, increasing the risk for torsades de pointes.(1) PREDISPOSING FACTORS: Pre-existing cardiovascular or cerebrovascular disease (e.g. heart failure, ischemic heart disease, history of myocardial infarction, stroke, or heart block), severe untreated sleep apnea, a prolonged QTc interval prior to siponimod initiation, factors associated with QTc prolongation (e.g. hypokalemia, hypomagnesemia), or concomitant treatment with QT prolonging agents may increase risk for cardiovascular toxicity due to siponimod. The risk of QT prolongation or torsades de pointes may also be increased in patients with a history of torsades de pointes, hypocalcemia, bradycardia, female gender, or advanced age.(3) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of the QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(3) PATIENT MANAGEMENT: Prior to initiation of siponimod, obtain an ECG to determine if preexisting conduction abnormalities are present.(1) Advice from a cardiologist is recommended in patients with preexisting heart and cerebrovascular conditions, prolonged QTc interval before or during the 6 hour observation, risk factors for QT prolongation, concurrent therapy with QT prolonging drugs or drugs that slow the heart rate or AV conduction.(1) In patients with heart rate (HR) less than 55 beats per minute (bpm), first- or second-degree AV block, or history of myocardial infarction or heart failure, first dose monitoring is recommended with hourly pulse and blood pressure to monitor for bradycardia for the first 6 hours. ECG monitoring is recommended prior to dosing and at the end of the observation period.(1) Additional US monitoring recommendations include: If HR is less than 45 bpm, the heart rate 6 hours postdose is at the lowest value postdose or if the ECG shows new onset of second degree or higher AV block at the end of the monitoring period, then monitoring should continue until the finding has resolved. If patient requires treatment for symptomatic bradycardia, second-degree or higher AV block, or QTc interval greater than or equal to 500 msec, perform continuous overnight ECG monitoring. Repeat the first dose monitoring strategy for the second dose of siponimod. If a titration dose is missed or if 4 or more consecutive daily doses are missed during maintenance treatment, reinitiate Day 1 of the dose titration and follow titration monitoring recommendations. Patient will need to be observed in the doctor's office or other facility for at least 6 hours after the first dose and after reinitiation if treatment is interrupted or discontinued for certain periods. Consult the prescribing information for full monitoring recommendations. United Kingdom recommendations:(3) In certain patients, it is recommended that an electrocardiogram (ECG) is obtained prior to dosing and at the end of the observation period. If post-dose bradyarrhythmia or conduction-related symptoms occur or if ECG 6 hours post-dose shows new onset second-degree or higher AV block or QTc > 500 msec, appropriate management should be initiated and observation continued until the symptoms/findings have resolved. If pharmacological treatment is required, monitoring should be continued overnight and 6-hour monitoring should be repeated after the second dose. During the first 6 days of treatment, if a titration dose is missed on one day, treatment needs to be re-initiated with a new titration pack. If there is a missed dose after day 6 the prescribed dose should be taken at the next scheduled time; the next dose should not be doubled. If maintenance treatment is interrupted for 4 or more consecutive daily doses, siponimod needs to be re-initiated with a new titration pack.(1,2) DISCUSSION: After the first dose of siponimod, heart rate decrease may begin within an hour. Decline is usually maximal at approximately 3-4 hours. With continued, chronic dosing, heart rate gradually returns to baseline in about 10 days.(1,2) A transient, dose-dependent decrease in heart rate was observed during the initial dosing phase of siponimod, which plateaued at doses greater than or equal to 5 mg, and bradyarrhythmic events (AV blocks and sinus pauses) were detected at a higher incidence under siponimod treatment than placebo. AV blocks and sinus pauses occurred above the recommended dose of 2 mg, with notably higher incidence under non-titrated conditions compared to dose titration conditions.(1) |
MAYZENT |
| Ponesimod/QT Prolonging Agents SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Ponesimod is a sphingosine 1-phosphate (S1P) receptor 1 modulator. Initiation of ponesimod has a negative chronotropic effect leading to a mean decrease in heart rate of 6 beats per minute (bpm) after the first dose. The first dose has also been associated with heart block.(1) CLINICAL EFFECTS: After a dose of ponesimod, a decrease in heart rate typically begins within an hour and reaches its nadir within 2-4 hours. The heart rate typically recovers to baseline levels 4-5 hours after administration. All patients recovered from bradycardia. The conduction abnormalities typically were transient, asymptomatic, and resolved within 24 hours. Second- and third-degree AV blocks were not reported. With up-titration after Day 1, the post-dose decrease in heart rate is less pronounced. Bradycardia may be associated with an increase in the QTc interval, increasing the risk for torsades de pointes.(1,2) PREDISPOSING FACTORS: Pre-existing cardiovascular or cerebrovascular disease (e.g. heart failure, ischemic heart disease, history of myocardial infarction, stroke, or heart block), severe untreated sleep apnea, a prolonged QTc interval prior to ponesimod initiation, factors associated with QTc prolongation, or concomitant treatment with QT prolonging agents may increase risk for cardiovascular toxicity due to ponesimod.(1) The risk of QT prolongation or torsades de pointes may also be increased in patients with a history of torsades de pointes, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of the QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: Prior to initiation of ponesimod, obtain an ECG to determine if preexisting conduction abnormalities are present. Ponesimod is generally not recommended in patients who are receiving concurrent treatment with a QT prolonging agent, anti-arrhythmic drugs, or drugs that may decrease heart rate. Consultation with a cardiologist is recommended.(1) In patients with heart rate (HR) less than 55 beats per minute (bpm), first- or second-degree AV block, or history of myocardial infarction or heart failure, monitor patients for 4 hours after the first dose for signs and symptoms of bradycardia with a minimum of hourly pulse and blood pressure measurements. Obtain an ECG in these patients prior to dosing and at the end of the 4-hour observation period.(1) Additional US monitoring recommendations include: If HR is less than 45 bpm, the heart rate 4 hours post-dose is at the lowest value post-dose or if the ECG shows new onset of second degree or higher AV block at the end of the monitoring period, then monitoring should continue until the finding has resolved. If patient requires treatment for symptomatic bradycardia, second-degree or higher AV block, or QTc interval greater than or equal to 500 msec, perform continuous overnight ECG monitoring and repeat the first dose monitoring strategy for the second dose of ponesimod. Consult the prescribing information for full monitoring recommendations. If fewer than 4 consecutive doses are missed during titration: resume treatment with the first missed titration dose and resume the titration schedule at that dose and titration day. If fewer than 4 consecutive doses are missed during maintenance: resume treatment with the maintenance dosage. If 4 or more consecutive daily doses are missed during treatment initiation or maintenance treatment, reinitiate Day 1 of the dose titration (new starter pack) and follow first-dose monitoring recommendations. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: After the first dose of ponesimod, heart rate decrease may begin within the first hour. Decline is usually maximal at approximately 4 hours. With continued, chronic dosing, post-dose decrease in heart rate is less pronounced. Heart rate gradually returns to baseline in about 4-5 hours.(1) |
PONVORY |
| Ozanimod/QT Prolonging Agents SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Ozanimod is a sphingosine 1-phosphate (S1P) receptor modulator. Initiation of ozanimod has a negative chronotropic effect leading to a mean decrease in heart rate of 13 beats per minute (bpm) after the first dose. The first dose has also been associated with heart block.(1,2) Ozanimod blocks the capacity of lymphocytes to egress from lymph nodes, reducing the number of lymphocytes in peripheral blood. The mechanism by which ozanimod exerts therapeutic effects in multiple sclerosis is unknown but may involve the reduction of lymphocyte migration into the central nervous system. CLINICAL EFFECTS: The initial heart rate lowering effect of ozanimod usually occurs within 5 hours. With continued up-titration, the maximal heart rate effect of ozanimod occurred on Day 8. Symptomatic bradycardia and heart block, including third degree block, have been observed. Bradycardia may be associated with an increase in the QTc interval, increasing the risk for torsades de pointes.(1,2) PREDISPOSING FACTORS: Pre-existing cardiovascular or cerebrovascular disease (e.g. heart failure, ischemic heart disease, history of myocardial infarction, stroke, or heart block), severe untreated sleep apnea, a prolonged QTc interval prior to ozanimod initiation, factors associated with QTc prolongation (e.g. hypokalemia, hypomagnesemia), or concomitant treatment with QT prolonging agents may increase risk for cardiovascular toxicity due to ozanimod.(1,2) The risk of QT prolongation or torsades de pointes may also be increased in patients with a history of torsades de pointes, hypocalcemia, bradycardia, female gender, or advanced age.(3) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of the QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(3) PATIENT MANAGEMENT: Prior to initiation of ozanimod, obtain an ECG to determine if preexisting conduction abnormalities are present. Patients with preexisting cardiac conditions, significant QT prolongation (QTc >450 msec in males, >470 msec in females), concurrent Class Ia or Class III antiarrhythmics, or receiving concurrent treatment with a QT prolonging agent at the time ozanimod is initiated or resumed should be referred to a cardiologist.(1) The US recommendations state: Dose titration is recommended with initiation of ozanimod due to transient decrease in heart rate and AV conduction delays.(1) United Kingdom recommendations:(2) Due to the risk of transient decreases in HR with the initiation of ozanimod, first dose, 6-hour monitoring for signs and symptoms of symptomatic bradycardia is recommended in patients with resting HR <55 bpm, second-degree [Mobitz type I] AV block or a history of myocardial infarction or heart failure. Patients should be monitored with hourly pulse and blood pressure measurement during this 6-hour period. An ECG prior to and at the end of this 6-hour period is recommended. Additional monitoring after 6 hours is recommended in patients with: heart rate less than 45 bpm, heart rate at the lowest value post-dose (suggesting that the maximum decrease in HR may not have occurred yet), evidence of a new onset second-degree or higher AV block at the 6-hour post dose ECG, or QTc interval greater than 500 msec. In these cases, appropriate management should be initiated and observation continued until the symptoms/findings have resolved. Instruct patients to report any irregular heartbeat, dizziness, or fainting.(2,3) DISCUSSION: After the first dose of ozanimod heart rate decline is usually maximal at approximately 5 hours, returning to baseline at 6 hours. With continued, chronic dosing, maximum heart rate effect occurred on day 8.(1,2) |
ZEPOSIA |
| Tolterodine/QT Prolonging Agents SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Tolterodine has been observed to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1,2) CLINICAL EFFECTS: The concurrent use of tolterodine with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1,2) PREDISPOSING FACTORS: Patients who are CYP2D6 poor metabolizers may be at increased risk.(1,2) The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(3) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(3) PATIENT MANAGEMENT: The manufacturer of tolterodine states concurrent use agents known to prolong the QT interval should be used with caution. Consider close observation in patients with a known history of QT prolongation or patients taking antiarrhythmic medications.(1,2) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: In a study of the effect of tolterodine immediate release tablets, the effect on the QT interval appeared greater for 8 mg/day (two times the therapeutic dose) compared to 4 mg/day. Tolterodine 2 mg BID and tolterodine 4 mg BID increased the QTcF by 5.01 msec (0.28-9.74 msec) and 11.84 msec (7.11-16.58 msec), respectively. The change in QT interval was more pronounced in CYP2D6 poor metabolizers (PM) than extensive metabolizers (EMs).(1,2) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(4) |
TOLTERODINE TARTRATE, TOLTERODINE TARTRATE ER |
| Triclabendazole/QT Prolonging Agents SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Triclabendazole has been observed to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) Triclabendazole is partially metabolized by CYP1A2. Ciprofloxacin, propafenone, and vemurafenib are CYP1A2 inhibitors and may inhibit the CYP1A2 mediated metabolism of triclabendazole. CLINICAL EFFECTS: The concurrent use of triclabendazole with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(2) Hepatic impairment and concurrent use of CYP1A2 inhibitors may raise triclabendazole levels and increase the risk of QT prolongation.(1) PATIENT MANAGEMENT: The manufacturer of triclabendazole states concurrent use with agents known to prolong the QT interval should be used with caution. Monitor ECG in patients with a history of QTc prolongation, symptoms of long QT interval, electrolyte imbalances, concurrent CYP1A2 inhibitors, or hepatic impairment. If signs of a cardiac arrhythmia develop, stop treatment with triclabendazole and monitor ECG.(1) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: In a thorough QT study, a dose-dependent prolongation in the QTc interval was observed with triclabendazole. The largest placebo-corrected mean increase in QTc was 9.2 msec (upper limit of confidence interval (UCI): 12.2 msec) following oral administration of 10 mg/kg triclabendazole twice daily (at the recommended dose), and the largest placebo-corrected mean increase in QTc was 21.7 msec (UCI: 24.7 msec) following oral administration of 10 mg/kg triclabendazole twice daily for 3 days (3 times the approved recommended dosing duration).(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval but are generally accepted to have a risk of causing Torsades de Pointes. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or Torsades de Pointes in clinical trials and/or post-marketing reports.(3) |
EGATEN |
| Etrasimod/QT Prolonging Agents SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Etrasimod is a sphingosine-1-phosphate (S1P) receptor modulator. Initiation of etrasimod has a negative chronotropic effect, which may increase the risk of developing QT prolongation. CLINICAL EFFECTS: Initiation of etrasimod may result in a transient decrease in heart rate. A mean decrease in heart rate of 7.2 (8.98) beats per minute was seen 2 to 3 hours after the first dose. The first dose has also been associated with heart block. Symptomatic bradycardia has been observed. Bradycardia may be associated with an increase in the QTc interval, increasing the risk for torsades de pointes.(1) PREDISPOSING FACTORS: Pre-existing cardiovascular or cerebrovascular disease (e.g. heart failure, ischemic heart disease, history of myocardial infarction, stroke, or heart block), severe untreated sleep apnea, a prolonged QTc interval prior to etrasimod initiation, factors associated with QTc prolongation (e.g. hypokalemia, hypomagnesemia), or concomitant treatment with QT prolonging agents may increase risk for cardiovascular toxicity due to etrasimod. The risk of QT prolongation or torsades de pointes may also be increased in patients with a history of torsades de pointes, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of the QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: Prior to initiation of etrasimod, obtain an ECG to determine if preexisting conduction abnormalities are present.(1) Advice from a cardiologist is recommended in patients with preexisting heart and cerebrovascular conditions, prolonged QTc interval, risk factors for QT prolongation, concurrent therapy with QT prolonging drugs or drugs that slow the heart rate or AV conduction.(1) Monitor blood pressure during treatment.(1) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: Initiation of etrasimod may result in a transient decrease in heart rate or transient AV conduction delays.(1) A transient decrease in heart rate was observed during the initial dosing phase of etrasimod and bradyarrhythmic events (AV blocks) were detected at a higher incidence under etrasimod treatment than placebo.(1) |
VELSIPITY |
| Mavorixafor/QT Prolonging Agents SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Mavorixafor has been shown to prolong the QTc interval. Concurrent use with other agents that prolong the QTc interval may result in additive effects on the QTc interval.(1) CLINICAL EFFECTS: The concurrent use of mavorixafor with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1) PREDISPOSING FACTORS: The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsade de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsade de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(2) PATIENT MANAGEMENT: The manufacturer of mavorixafor states that concurrent use of mavorixafor with other agents known to prolong the QTc interval should be approached with caution. ECG monitoring is recommended prior to initiation, during concurrent therapy, and as clinically indicated with other agents known to prolong the QTc interval.(1) If QT prolongation occurs, a dose reduction or discontinuation of mavorixafor may be required.(1) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. DISCUSSION: In a thorough QT study, a dose of mavorixafor 800 mg increased the mean QTc 15.6 msec (upper 90% CI = 19.9 msec). The dose of mavorixafor was 2 times the recommended maximum daily dose.(1) Agents that are linked to this monograph may have varying degrees of potential to prolong the QTc interval. Agents linked to this monograph have been shown to prolong the QTc interval either through their mechanism of action, through studies on their effects on the QTc interval, or through reports of QTc prolongation and/or torsades de pointes in clinical trials and/or postmarketing reports.(3) |
XOLREMDI |
The following contraindication information is available for HALOPERIDOL (haloperidol):
Drug contraindication overview.
No enhanced Contraindications information available for this drug.
No enhanced Contraindications information available for this drug.
There are 6 contraindications.
Absolute contraindication.
| Contraindication List |
|---|
| Coma |
| Corticobasal degeneration |
| Drug-induced CNS depression |
| Extrapyramidal disease |
| Neuroleptic malignant syndrome |
| Parkinsonism |
There are 12 severe contraindications.
Adequate patient monitoring is recommended for safer drug use.
| Severe List |
|---|
| Angina |
| Congenital long QT syndrome |
| Hypokalemia |
| Hypomagnesemia |
| Pregnancy |
| Respiratory depression |
| Seizure disorder |
| Senile dementia |
| Tardive dyskinesia |
| Thyrotoxicosis crisis |
| Torsades de pointes |
| Untreated hypothyroidism |
There are 7 moderate contraindications.
Clinically significant contraindication, where the condition can be managed or treated before the drug may be given safely.
| Moderate List |
|---|
| Acquired dystonia |
| Disease of liver |
| Hypotension |
| Leukopenia |
| Neutropenic disorder |
| Tobacco smoker |
| Urinary retention |
The following adverse reaction information is available for HALOPERIDOL (haloperidol):
Adverse reaction overview.
No enhanced Common Adverse Effects information available for this drug.
No enhanced Common Adverse Effects information available for this drug.
There are 28 severe adverse reactions.
| More Frequent | Less Frequent |
|---|---|
| None. |
Decreased thirst Hallucinations Skin rash Tachycardia Tardive dyskinesia |
| Rare/Very Rare |
|---|
|
Accidental fall Agranulocytosis Akathisia Bronchospastic pulmonary disease Cataracts Extrapyramidal disease Heat stroke Hypertension Hyponatremia Jaundice Laryngismus Leukopenia Neuroleptic malignant syndrome Neutropenic disorder Orthostatic hypotension Parkinsonism Priapism Prolonged QT interval Retinal disorder Rhabdomyolysis Seizure disorder Torsades de pointes Ventricular arrhythmias |
There are 34 less severe adverse reactions.
| More Frequent | Less Frequent |
|---|---|
| None. |
Constipation Drowsy Erectile dysfunction Nausea Skin photosensitivity Visual changes Vomiting Xerostomia |
| Rare/Very Rare |
|---|
|
Acneiform eruption Acquired dystonia Acute cognitive impairment Agitation Alopecia Anorexia Anticholinergic toxicity Depression Diarrhea Dyspepsia Euphoria Fever Galactorrhea not associated with childbirth Gynecomastia Headache disorder Hyperhidrosis Hypotension Insomnia Irregular menstrual periods Lethargy Maculopapular rash Mastalgia Nervousness Urinary incontinence Urinary retention Vertigo |
The following precautions are available for HALOPERIDOL (haloperidol):
No enhanced Pediatric Use information available for this drug.
Contraindicated
Severe Precaution
Management or Monitoring Precaution
Contraindicated
| None |
Severe Precaution
| None |
Management or Monitoring Precaution
| None |
Although there are no adequate and controlled studies to date in humans, 2 cases of limb malformations (e.g., phocomelia) have occurred in offspring of women who were given haloperidol concurrently with other potentially teratogenic drugs during the first trimester of pregnancy; these teratogenic effects have not been directly attributed to haloperidol. Haloperidol has been shown to be teratogenic and fetotoxic in animals at dosages 2-20 times the usual maximum human dosage. Neonates exposed to antipsychotic agents, including haloperidol, during the third trimester of pregnancy are at risk for extrapyramidal and/or withdrawal symptoms following delivery.
Symptoms reported in these neonates to date include agitation, hypertonia, hypotonia, tardive dyskinetic-like symptoms, tremor, somnolence, respiratory distress, and feeding disorder. Any neonate exhibiting extrapyramidal or withdrawal symptoms following in utero exposure to antipsychotic agents should be monitored. Symptoms were self-limiting in some neonates, but varied in severity; some infants required intensive care unit support and prolonged hospitalization.
For further information on extrapyramidal and withdrawal symptoms in neonates, see Cautions: Pregnancy, Fertility, and Lactation, in the Phenothiazines General Statement 28:16.08.24. Haloperidol should be used during pregnancy or in women likely to become pregnant only when the potential benefits justify the possible risks to the fetus.
Symptoms reported in these neonates to date include agitation, hypertonia, hypotonia, tardive dyskinetic-like symptoms, tremor, somnolence, respiratory distress, and feeding disorder. Any neonate exhibiting extrapyramidal or withdrawal symptoms following in utero exposure to antipsychotic agents should be monitored. Symptoms were self-limiting in some neonates, but varied in severity; some infants required intensive care unit support and prolonged hospitalization.
For further information on extrapyramidal and withdrawal symptoms in neonates, see Cautions: Pregnancy, Fertility, and Lactation, in the Phenothiazines General Statement 28:16.08.24. Haloperidol should be used during pregnancy or in women likely to become pregnant only when the potential benefits justify the possible risks to the fetus.
Haloperidol is distributed into milk. The manufacturers warn that nursing should not be undertaken by women receiving haloperidol.
No enhanced Geriatric Use information available for this drug.
The following prioritized warning is available for HALOPERIDOL (haloperidol):
WARNING: There may be a slightly increased risk of serious, possibly fatal side effects (such as heart failure, fast/irregular heartbeat, pneumonia) when this medication is used by older adults with dementia. This medication is not approved for the treatment of dementia-related behavior problems. Discuss the risks and benefits of this medication, as well as other effective and possibly safer treatments for dementia-related behavior problems, with the doctor.
WARNING: There may be a slightly increased risk of serious, possibly fatal side effects (such as heart failure, fast/irregular heartbeat, pneumonia) when this medication is used by older adults with dementia. This medication is not approved for the treatment of dementia-related behavior problems. Discuss the risks and benefits of this medication, as well as other effective and possibly safer treatments for dementia-related behavior problems, with the doctor.
The following icd codes are available for HALOPERIDOL (haloperidol)'s list of indications:
| Gilles de la tourette syndrome | |
| F95.2 | Tourette's disorder |
| Psychotic disorder | |
| F06.0 | Psychotic disorder with hallucinations due to known physiological condition |
| F06.2 | Psychotic disorder with delusions due to known physiological condition |
| F23 | Brief psychotic disorder |
| F24 | Shared psychotic disorder |
| Schizophrenia | |
| F20 | Schizophrenia |
| F20.0 | Paranoid schizophrenia |
| F20.1 | Disorganized schizophrenia |
| F20.2 | Catatonic schizophrenia |
| F20.3 | Undifferentiated schizophrenia |
| F20.5 | Residual schizophrenia |
| F20.8 | Other schizophrenia |
| F20.81 | Schizophreniform disorder |
| F20.89 | Other schizophrenia |
| F20.9 | Schizophrenia, unspecified |
Formulary Reference Tool