Robafen Dm Cough

Drug overview for ROBAFEN DM COUGH (guaifenesin/dextromethorphan hbr):

Generic name: GUAIFENESIN/DEXTROMETHORPHAN HBR (gweye-FEN-eh-sin/dex-trow-meth-OR-fan)
Drug class: Expectorants
Therapeutic class: Respiratory Therapy Agents

No enhanced Introduction information available for this drug.

No enhanced Uses information available for this drug.

DRUG IMAGES

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The following indications for ROBAFEN DM COUGH (guaifenesin/dextromethorphan hbr) have been approved by the FDA:

Indications:
Cough

Professional Synonyms:
None.

Generic dosing information for GUAIFENESIN-DEXTROMETHORPHAN
DRUG LABEL	DOSING TYPE	DOSING INSTRUCTIONS
GUAIFENESN-DM 100-10MG/5ML CUP	Maintenance	Adults take 10 milliliters by oral route every 4 hours as needed
GUAIFENSN-DM 200-20MG/10ML CUP	Maintenance	Adults take 10 milliliters by oral route every 4 hours as needed
GUAIFENESIN-DM 100-10 MG/5 ML	Maintenance	Adults take 10 milliliters by oral route every 4 hours as needed

The following drug interaction information is available for ROBAFEN DM COUGH (guaifenesin/dextromethorphan hbr):

Contraindicated
Severe
Moderate

There are 3 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
Selected Opioids; Dextromethorphan/Selected MAOIs 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: Selected opioids inhibit neural reuptake of serotonin. MAOIs may increase neuronal serotonin concentrations via inhibition of MAO-A.(26) CLINICAL EFFECTS: The concurrent use of selected opioids with MAOIs has resulted in hypotension, hyperpyrexia, sedation, somnolence, and death. Symptoms of serotonin syndrome may include tremor, agitation, diaphoresis, hyperreflexia, clonus, tachycardia, hyperthermia, and muscle rigidity.(26) PREDISPOSING FACTORS: Higher opioid concentrations as may occur due to inhibition of opioid clearance, patient specific genomic factors (e.g. poor metabolizer status for a P450 enzyme), or high opioid dosage may increase the risk for a severe interaction. PATIENT MANAGEMENT: Dextromethorphan, diamorphine, meperidine, and tapentadol should not be used in patients taking MAOIs. Use alternative agents for cough or pain. The US manufacturer of Nuedexta(dextromethorphan-quinidine) states Nuedexta is contraindicated within 14 days of MAOI administration.(28) Quinidine increases systemic dextromethorphan concentrations 10 to 20-fold. Other strong CYP2D6 inhibitors such as bupropion, fluoxetine and paroxetine could similarly increase dextromethorphan levels. The US manufacturer of selegiline states that concurrent use with dextromethorphan or meperidine is contraindicated. The US manufacturers of meperidine and tapentadol and the UK manufacturer of diamorphine state that they should not be used concurrently with or within 14 days of taking an MAOI. DISCUSSION: The interaction between meperidine and MAOIs has been well documented. There are at least two reports of potential interactions between MAOIs and dextromethorphan. Concomitant use of quinidine, a strong CYP2D6 inhibitor, increases systemic dextromethorphan concentrations 10 to 20-fold. Other strong CYP2D6 inhibitors such as bupropion, fluoxetine and paroxetine could similarly increase dextromethorphan levels and risk for serotonin toxicity in patients also receiving MAOIs. Methylene blue, when administered intravenously, has been shown to reach sufficient concentrations to be a potent inhibitor of MAO-A. 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.	AZILECT, EMSAM, MARPLAN, METHYLENE BLUE, NARDIL, PARNATE, PHENELZINE SULFATE, PROVAYBLUE, RASAGILINE MESYLATE, SELEGILINE HCL, TRANYLCYPROMINE SULFATE, XADAGO, ZELAPAR
Dextromethorphan/Metaxalone 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: Dextromethorphan inhibits neural reuptake of serotonin. Metaxalone, a weak inhibitor of MAO, may increase neuronal serotonin concentrations.(1) CLINICAL EFFECTS: The concurrent use of dextromethorphan with MAOIs may result in hypotension, hyperpyrexia, sedation, somnolence, and death. Symptoms of serotonin syndrome may include tremor, agitation, diaphoresis, hyperreflexia, clonus, tachycardia, hyperthermia, and muscle rigidity.(1) PREDISPOSING FACTORS: Higher opioid concentrations as may occur due to inhibition of opioid clearance, patient specific genomic factors (e.g. poor metabolizer status for a P450 enzyme), or high opioid dosage may increase the risk for a severe interaction. PATIENT MANAGEMENT: Dextromethorphan should not be used in patients taking MAOIs such as metaxalone. Use alternative agents for cough. The US manufacturer of Nuedexta (dextromethorphan-quinidine) states Nuedexta is contraindicated within 14 days of MAOI administration.(1) Quinidine increases systemic dextromethorphan concentrations 10 to 20-fold. DISCUSSION: Metaxalone is a weak inhibitor of MAO.(2,3) There are at least two reports of potential interactions between MAOIs and dextromethorphan. Concomitant use of quinidine, a strong CYP2D6 inhibitor, increases systemic dextromethorphan concentrations 10 to 20-fold. Other strong CYP2D6 inhibitors such as bupropion, fluoxetine and paroxetine could similarly increase dextromethorphan levels and risk for serotonin toxicity in patients also receiving MAOIs.(4,5)	METAXALONE
Selected CYP2D6 Substrates/Mavorixafor 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: Mavorixafor is a strong inhibitor of CYP2D6 and is expected to inhibit the metabolism of agents through this pathway.(1) CLINICAL EFFECTS: Concurrent use of mavorixafor may result in elevated levels of and toxicity from agents metabolized by CYP2D6.(1) PREDISPOSING FACTORS: With tricyclic antidepressants, 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 and anorectics; diabetics treated with oral hypoglycemics or insulin; or with concomitant medications known to lower seizure threshold (antipsychotics, theophylline, systemic steroids). With anticholinergic agents, 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.(2) PATIENT MANAGEMENT: The US manufacturer of mavorixafor states concurrent use with CYP2D6 substrate that are highly dependent on CYP2D6 metabolism is contraindicated.(1) The US manufacturer of doxepin states if concurrent use of doxepin and strong CYP2D6 inhibitors such as mavorixafor is warranted, monitor doxepin plasma concentrations and reduce the doxepin dose based on doxepin plasma concentrations.(5) DISCUSSION: Mavorixafor (400 mg) increased dextromethorphan (CYP2D6 substrate) maximum concentration (Cmax) and area-under-curve (AUC) by 6-fold and 9-fold, respectively.(1) Selected CYP2D6 substrates linked to this monograph include: aripiprazole, atomoxetine, brexpiprazole, desipramine, deutetrabenazine, dextromethorphan, doxepin, encainide, fenfluramine, metoclopramide, methoxyphenamine, metoprolol, mexiletine, nebivolol, paroxetine, perphenazine, risperidone, tetrabenazine, trimipramine, venlafaxine, and yohimbine.	XOLREMDI

There are 1 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
Selected CYP1A2 or CYP2D6 Substrates/Givosiran SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Givosiran interferes with the first and rate-limiting step in hepatic heme biosynthesis, which may lower hepatic heme levels and decrease production and/or activity of cytochrome P450 enzymes.(1,2) CLINICAL EFFECTS: Concurrent use of givosiran may result in elevated levels of and toxicity from agents metabolized by CYP1A2 or CYP2D6.(1) PREDISPOSING FACTORS: With tricyclic antidepressants, 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 and anorectics; diabetics treated with oral hypoglycemics or insulin; or with concomitant medications known to lower seizure threshold (antipsychotics, theophylline, systemic steroids). With anticholinergic agents, 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: Avoid the concurrent use of givosiran with agents that are sensitive substrates of CYP1A2 or CYP2D6, or CYP1A2 or CYP2D6 substrates with a narrow therapeutic index. If concurrent use is unavoidable, decrease the dose of the CYP1A2 or CYP2D6 substrate and monitor patients for toxicity. DISCUSSION: A study of 9 patients with acute intermittent porphyria found that givosiran decreased the maximum concentration (Cmax) and area-under-curve (AUC) of caffeine (a CYP1A2 substrate) by 1.3- and 3.1-fold, respectively, compared to caffeine alone. Givosiran also decreased the Cmax and AUC of dextromethorphan (a CYP2D6 substrate) by 2- and 2.4-fold, respectively, compared to dextromethorphan alone.(1,2) Selected CYP2D6 substrates linked to this monograph include: atomoxetine, desipramine, deutetrabenazine, dextromethorphan, doxepin, encainide, methoxyphenamine, metoprolol, nebivolol, nefazodone, paroxetine, perphenazine, risperidone, tetrabenazine, trimipramine, and venlafaxine. Selected CYP1A2 substrates linked to this monograph include: agomelatine, aminophylline, rasagiline, tacrine, theophylline, tizanidine, and yohimbine.	GIVLAARI

Drug Interaction

Drug Names

Selected CYP1A2 or CYP2D6 Substrates/Givosiran

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: Givosiran interferes with the first and rate-limiting step in hepatic heme biosynthesis, which may lower hepatic heme levels and decrease production and/or activity of cytochrome P450 enzymes.(1,2)

CLINICAL EFFECTS: Concurrent use of givosiran may result in elevated levels of and toxicity from agents metabolized by CYP1A2 or CYP2D6.(1)

PREDISPOSING FACTORS: With tricyclic antidepressants, 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 and anorectics; diabetics treated with oral hypoglycemics or insulin; or with concomitant medications known to lower seizure threshold (antipsychotics, theophylline, systemic steroids). With anticholinergic agents, 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: Avoid the concurrent use of givosiran with agents that are sensitive substrates of CYP1A2 or CYP2D6, or CYP1A2 or CYP2D6 substrates with a narrow therapeutic index. If concurrent use is unavoidable, decrease the dose of the CYP1A2 or CYP2D6 substrate and monitor patients for toxicity.

DISCUSSION: A study of 9 patients with acute intermittent porphyria found that givosiran decreased the maximum concentration (Cmax) and area-under-curve (AUC) of caffeine (a CYP1A2 substrate) by 1.3- and 3.1-fold, respectively, compared to caffeine alone.

Givosiran also decreased the Cmax and AUC of dextromethorphan (a CYP2D6 substrate) by 2- and 2.4-fold, respectively, compared to dextromethorphan alone.(1,2) Selected CYP2D6 substrates linked to this monograph include: atomoxetine, desipramine, deutetrabenazine, dextromethorphan, doxepin, encainide, methoxyphenamine, metoprolol, nebivolol, nefazodone, paroxetine, perphenazine, risperidone, tetrabenazine, trimipramine, and venlafaxine. Selected CYP1A2 substrates linked to this monograph include: agomelatine, aminophylline, rasagiline, tacrine, theophylline, tizanidine, and yohimbine.

GIVLAARI

There are 5 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
Dextromethorphan/Selected SSRIs that Inhibit CYP2D6 SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Fluoxetine and paroxetine, strong inhibitors of CYP2D6, may inhibit the metabolism of dextromethorphan.(1-4) CLINICAL EFFECTS: Patients may experience increased adverse effects of dextromethorphan due to elevated systemic concentrations. Concomitant use of two or more serotonergic agents increases the risk for serotonin syndrome. Serotonin syndrome constitutes a range of toxicities from mild to life threatening.(5) Mild serotonin symptoms may include: shivering, diaphoresis, mydriasis, intermittent tremor, and/or myoclonus.(5) Moderate serotonin symptoms may include: tachycardia, hypertension, hyperthermia, mydriasis, diaphoresis, hyperactive bowel sounds, hyperreflexia, and/OR clonus.(5) Severe serotonin symptoms may include: severe hypertension and tachycardia, shock, agitated delirium, muscular rigidity, and/or hypertonicity.(5) PREDISPOSING FACTORS: Concurrent use of additional drugs which increase CNS serotonin levels would be expected to further increase risk for serotonin syndrome.(5) PATIENT MANAGEMENT: Monitor patients on multiple serotonergic agents for symptoms of serotonin toxicity. Patients in whom serotonin syndrome is suspected should receive immediate medical attention. If the interacting agents are prescribed by different providers, it would be prudent to assure that both are aware of concomitant therapy and monitoring the patient for serotonin toxicities. Advise patients not to exceed recommended dosages of dextromethorphan. If concurrent therapy is warranted, patients should be monitored for signs and symptoms of serotonin syndrome. Instruct patients to report muscle twitching, tremors, shivering and stiffness, fever, heavy sweating, heart palpitations, restlessness, confusion, agitation, trouble with coordination, and/or severe diarrhea. DISCUSSION: An open label parallel group trial evaluated the interaction between dextromethorphan-quinidine 30 mg-30 mg (higher than marketed strength of 20 mg-10 mg) and paroxetine 20 mg in 27 healthy volunteers with a mean age of 33.6 years. Subjects were randomly divided into 2 groups: - Group 1 received paroxetine 20 mg once daily for 12 days, followed by the addition of dextromethorphan-quinidine twice daily for 8 days. - Group 2 received dextromethorphan-quinidine twice daily for 8 days, followed by paroxetine 20 mg daily for 12 days. Results: overall, adverse effects were reported in 19 of 26 subjects who received combination therapy (73%) and 15 of 27 subjects who received monotherapy (56%). Adverse effects from the combination differed somewhat between groups and were more closely associated with the second drug product administered. Group 1 reported dizziness, headache, somnolence, euphoria, nausea, and vomiting after the addition of dextromethorphan-quinidine to paroxetine. Group 2 adverse events were dizziness, headache, nausea, vomiting, insomnia, anxiety, and hyperhidrosis after the addition of paroxetine to dextromethorphan.(1) Two weeks of fluoxetine therapy increased the area-under-curve (AUC) of dextromethorphan by 27-fold.(4) Serotonin syndrome has been reported in patients following the addition of dextromethorphan containing cough syrups to fluoxetine(6,7) and paroxetine.(8)	FLUOXETINE DR, FLUOXETINE HCL, OLANZAPINE-FLUOXETINE HCL, PAROXETINE CR, PAROXETINE ER, PAROXETINE HCL, PAROXETINE MESYLATE, PAXIL, PAXIL CR, PROZAC
Selected CYP2D6 Substrates/Desvenlafaxine SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Desvenlafaxine is considered a weak inhibitor of CYP2D6.(1) CLINICAL EFFECTS: Concurrent use of desvenlafaxine may lead to increased serum levels and adverse effects of drugs sensitive to inhibition of the CYP2D6 pathway.(1) Agents linked to this monograph are: atomoxetine, dapoxetine, deutetrabenazine, dextromethorphan, metoprolol, nebivolol, perphenazine, tolterodine, and yohimbine. PREDISPOSING FACTORS: With perphenazine and tolterodine, 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.(2) PATIENT MANAGEMENT: Reduce the dose of CYP2D6 substrates by up to one-half when coadministered with desvenlafaxine 400 mg.(1) Studies have shown that desvenlafaxine does not have a clinically relevant effect on CYP2D6 metabolism at the dose of 100 mg daily. CYP2D6 substrates should be dosed at the original level when coadministered with desvenlafaxine 100 mg or lower or when desvenlafaxine is discontinued.(1) The manufacturer of desvenlafaxine does not provide recommendations for use of desvenlafaxine at dosages between 100-400 mg concurrently with CYP2D6 substrates. Monitor for toxicity of the CYP2D6 substrate and consider reducing its dosage. DISCUSSION: In a study, coadministration of desvenlafaxine 100 mg daily with desipramine (single dose 50 mg) increased desipramine's maximum concentration (Cmax) and area-under-the-curve (AUC)by 25% and 17%.(1) In a study, coadministration of desvenlafaxine 400 mg daily with desipramine (single dose 50 mg) increased desipramine's maximum concentration (Cmax) and area-under-the-curve (AUC)by 50% and 90%.(1) Selected CYP2D6 substrates linked to this monograph are: atomoxetine, dapoxetine, deutetrabenazine, dextromethorphan, metoprolol, nebivolol, perphenazine, tolterodine, and yohimbine.	DESVENLAFAXINE ER, DESVENLAFAXINE SUCCINATE ER, PRISTIQ
Dextromethorphan/Selected Serotonergic Agents SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Dextromethorphan inhibits neuronal reuptake of serotonin. Concurrent administration with one or more serotonergic agents may increase serotonin effects, leading to serotonin toxicity.(1-11) CLINICAL EFFECTS: The concurrent use of dextromethorphan with serotonergic agents may increase the risk for serotonin syndrome. Serotonin syndrome constitutes a range of toxicities from mild to life threatening.(3) Mild serotonin symptoms may include: shivering, diaphoresis, mydriasis, intermittent tremor, and/or myoclonus.(3) Moderate serotonin symptoms may include: tachycardia, hypertension, hyperthermia, mydriasis, diaphoresis, hyperactive bowel sounds, hyperreflexia, and/OR clonus.(3) Severe serotonin symptoms may include: severe hypertension and tachycardia, shock, agitated delirium, muscular rigidity, and/or hypertonicity.(3) PREDISPOSING FACTORS: Concurrent use of additional drugs which increase CNS serotonin levels would be expected to further increase risk for serotonin syndrome.(1-11) PATIENT MANAGEMENT: Monitor patients on multiple serotonergic agents for symptoms of serotonin toxicity. Patients in whom serotonin syndrome is suspected should receive immediate medical attention. If the interacting agents are prescribed by different providers, it would be prudent to assure that both are aware of concomitant therapy and monitoring the patient for serotonin toxicities. Advise patients not to exceed recommended dosages of dextromethorphan. If concurrent therapy is warranted, patients should be monitored for signs and symptoms of serotonin syndrome. Instruct patients to report muscle twitching, tremors, shivering and stiffness, fever, heavy sweating, heart palpitations, restlessness, confusion, agitation, trouble with coordination, or severe diarrhea. DISCUSSION: Dextromethorphan inhibits neuronal reuptake of serotonin and may potentially precipitate dose-dependant serotonin toxicity in conjunction with other serotonergic agents.(4,5) Serotonin syndrome has been reported in patients following the addition of dextromethorphan containing cough syrups to duloxetine,(6) escitalopram,(7) fluoxetine,(8,9) paroxetine,(10) and sertraline.(11) Selected serotonergic agents linked to this monograph include: centanafadine, citalopram, clomipramine, duloxetine, escitalopram, fluvoxamine, imipramine, levomilnacipran, milnacipran, sertraline, venlafaxine, vilazodone and vortioxetine.	ANAFRANIL, CELEXA, CITALOPRAM HBR, CLOMIPRAMINE HCL, DRIZALMA SPRINKLE, DULOXETINE HCL, EFFEXOR XR, ESCITALOPRAM OXALATE, EXXUA, FETZIMA, FLUVOXAMINE MALEATE, FLUVOXAMINE MALEATE ER, IMIPRAMINE HCL, IMIPRAMINE PAMOATE, LEXAPRO, MILNACIPRAN HCL, SAVELLA, SERTRALINE HCL, TRINTELLIX, VENLAFAXINE BESYLATE ER, VENLAFAXINE HCL, VENLAFAXINE HCL ER, VIIBRYD, VILAZODONE HCL, ZOLOFT
Dextromethorphan/Selected Strong CYP2D6 Inhibitors SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Strong inhibitors of CYP2D6 may inhibit the metabolism of dextromethorphan.(1-4) CLINICAL EFFECTS: Patients may experience increased adverse effects of dextromethorphan due to elevated systemic concentrations. Elevated levels of dextromethorphan or concomitant use of two or more serotonergic agents increases the risk for serotonin syndrome. Serotonin syndrome constitutes a range of toxicities from mild to life threatening.(5) Mild serotonin symptoms may include: shivering, diaphoresis, mydriasis, intermittent tremor, and/or myoclonus.(5) Moderate serotonin symptoms may include: tachycardia, hypertension, hyperthermia, mydriasis, diaphoresis, hyperactive bowel sounds, hyperreflexia, and/OR clonus.(5) Severe serotonin symptoms may include: severe hypertension and tachycardia, shock, agitated delirium, muscular rigidity, and/or hypertonicity.(5) PREDISPOSING FACTORS: Concurrent use of additional drugs which increase CNS serotonin levels would be expected to further increase risk for serotonin syndrome.(5) PATIENT MANAGEMENT: Monitor patients for elevated dextromethorphan levels or on multiple serotonergic agents for symptoms of serotonin toxicity. Patients in whom serotonin syndrome is suspected should receive immediate medical attention. If the interacting agents are prescribed by different providers, it would be prudent to assure that both are aware of concomitant therapy and monitoring the patient for serotonin toxicities. Advise patients not to exceed recommended dosages of dextromethorphan. If concurrent therapy is warranted, patients should be monitored for signs and symptoms of serotonin syndrome. Instruct patients to report muscle twitching, tremors, shivering and stiffness, fever, heavy sweating, heart palpitations, restlessness, confusion, agitation, trouble with coordination, or severe diarrhea. DISCUSSION: An open label parallel group trial evaluated the interaction between dextromethorphan-quinidine 30 mg-30 mg (higher than marketed strength of 20 mg-10 mg) and paroxetine 20 mg in 27 healthy volunteers with a mean age of 33.6 years. Subjects were randomly divided into 2 groups: - Group 1 received paroxetine 20 mg once daily for 12 days, followed by the addition of dextromethorphan-quinidine twice daily for 8 days. - Group 2 received dextromethorphan-quinidine twice daily for 8 days, followed by paroxetine 20 mg daily for 12 days. Results: overall, adverse effects were reported in 19 of 26 subjects who received combination therapy (73%) and 15 of 27 subjects who received monotherapy (56%). Adverse effects from the combination differed somewhat between groups and were more closely associated with the second drug product administered. Group 1 reported dizziness, headache, somnolence, euphoria, nausea, and vomiting after the addition of dextromethorphan-quinidine to paroxetine. Group 2 adverse events were dizziness, headache, nausea, vomiting, insomnia, anxiety, and hyperhidrosis after the addition of paroxetine to dextromethorphan.(1) Two weeks of fluoxetine therapy increased the area-under-curve (AUC) of dextromethorphan by 27-fold.(4) Serotonin syndrome has been reported in patients following the addition of dextromethorphan containing cough syrups to fluoxetine(6,7) and paroxetine.(8) Selected strong CYP2D6 inhibitors linked to this monograph include: bupropion, dacomitinib, hydroquinidine, quinidine, and terbinafine.(8)	APLENZIN, BUPROPION HCL, BUPROPION HCL SR, BUPROPION XL, CONTRAVE, DEXTROMETHORPHAN HBR-QUINIDINE, NUEDEXTA, QUINIDINE GLUCONATE, QUINIDINE SULFATE, TERBINAFINE HCL, WELLBUTRIN SR, WELLBUTRIN XL
Ziprasidone/Serotonergic Agents SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Ziprasidone is a 5-HT1A agonist and serotonin and norepinephrine reuptake inhibitor. Concurrent administration with one or more serotonergic agents may increase serotonin effects, resulting in serotonin toxicity.(1,2) CLINICAL EFFECTS: Concurrent use of ziprasidone and other serotonergic agents may result in serotonin syndrome, a potentially life-threatening condition with symptoms including altered mental status, hypertension, restlessness, myoclonus, hyperthermia, hyperreflexia, diaphoresis, shivering, and tremor.(1) PREDISPOSING FACTORS: Serotonin syndrome risk is dose-related. Higher systemic concentrations of either drug would be predicted to increase risk for serotonin toxicity.(2) Concomitant therapy with multiple agents which increase brain serotonin concentrations may also increase risk for serotonin syndrome.(2) PATIENT MANAGEMENT: Caution patients about the risk of serotonin syndrome with the concomitant use of ziprasidone with other serotonergic drugs. Instruct patients to contact their healthcare provider, or report to the emergency room, should they experience signs or symptoms of serotonin syndrome.(1) DISCUSSION: Several cases of serotonin syndrome have been reported in patients receiving ziprasidone.(4-6)	GEODON, ZIPRASIDONE HCL, ZIPRASIDONE MESYLATE

Severe List
Systemic mastocytosis

Moderate List
No disease contraindications

The following adverse reaction information is available for ROBAFEN DM COUGH (guaifenesin/dextromethorphan hbr):

Overview
Severe
Less Severe

Adverse reaction overview.

No enhanced Common Adverse Effects information available for this drug.

There are 1 severe adverse reactions.

More Frequent	Less Frequent
None.	None.

Rare/Very Rare
Vomiting

There are 8 less severe adverse reactions.

More Frequent	Less Frequent
None.	Acute cognitive impairment

Rare/Very Rare
Abdominal pain with cramps Anticholinergic toxicity Dizziness Drowsy Gastrointestinal irritation Nausea Vomiting

The following precautions are available for ROBAFEN DM COUGH (guaifenesin/dextromethorphan hbr):

Pediatric
Pregnant
Lactation
Geriatric

No enhanced Pediatric Use information available for this drug.

Contraindicated

None

Severe Precaution

None

Management or Monitoring Precaution

None

No enhanced Pregnancy information available for this drug.

No enhanced Lactation information available for this drug.

No enhanced Geriatric Use information available for this drug.

Cough
R05	Cough
R05.1	Acute cough
R05.2	Subacute cough
R05.3	Chronic cough
R05.9	Cough, unspecified