Poly Hist Forte

Drug overview for POLY HIST FORTE (doxylamine succinate/phenylephrine hcl):

Generic name: DOXYLAMINE SUCCINATE/PHENYLEPHRINE HCL
Drug class: Amphetamines/Anorexiants/Stimulants
Therapeutic class: Respiratory Therapy Agents

Doxylamine is an ethanolamine-derivative, first generation antihistamine. Phenylephrine hydrochloride is a sympathomimetic amine that predominantly acts by a direct effect on alpha1-adrenergic receptors.

Doxylamine succinate shares the actions and uses of other antihistamines.

DRUG IMAGES

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The following indications for POLY HIST FORTE (doxylamine succinate/phenylephrine hcl) have been approved by the FDA:

Indications:
Allergic conjunctivitis
Allergic rhinitis
Cold symptoms
Nasal congestion
Perennial allergic rhinitis
Rhinorrhea
Seasonal allergic rhinitis
Sneezing
Vasomotor rhinitis

Professional Synonyms:
Allergy eye itch
Atopic conjunctivitis
Atopic rhinitis
Intermittent allergic rhinitis
Itchy eyes due to allergies
Nasal stuffiness
Non-seasonal allergic rhinitis
Ocular itching due to allergies
Periodic runny nose
Seasonal allergy

The following drug interaction information is available for POLY HIST FORTE (doxylamine succinate/phenylephrine hcl):

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
Sympathomimetics (Indirect & Mixed Acting)/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: Catecholamine stores increased by MAOIs can be released by indirect acting sympathomimetics such as ephedrine and amphetamine. MAO inhibitors also interfere with gut and liver metabolism of direct acting sympathomimetics (e.g oral phenylephrine). CLINICAL EFFECTS: Concurrent use of MAOIs may result in potentiation of sympathomimetic effects, which may result in headaches, hypertensive crisis, toxic neurological effects, and malignant hyperpyrexia. Fatalities have occurred. PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: Concurrent use of monoamine oxidase inhibitors and sympathomimetics is contraindicated. The manufacturers of sympathomimetic agents recommend waiting 14 days after discontinuation of MAO inhibitors before initiating the sympathomimetic. DISCUSSION: Indirect acting sympathomimetic amines may cause abrupt elevation of blood pressure when administered to patients taking monoamine oxidase inhibitors, resulting in a potentially fatal hypertensive crisis. Mixed (direct and indirect) acting sympathomimetics have also been shown to interact with monoamine oxidase inhibitors depending on their degree of indirect action. The direct-acting sympathomimetics have not been reported to interact. Dopamine is metabolized by monoamine oxidase, and its pressor effect is enhanced by monoamine oxidase inhibitors. Since procarbazine, an antineoplastic agent, is a weak monoamine oxidase inhibitor, hypertensive reactions may result from its concurrent use with indirect and mixed acting sympathomimetics. Furazolidone, an antibacterial with monoamine oxidase inhibitor action, has also been shown to interact with indirect acting sympathomimetics. Linezolid is another antibacterial with monoamine oxidase inhibitor properties. Metaxalone is a weak inhibitor of MAO. Foods containing large amounts of tyramine have also been implicated in this interaction. Methylene blue, when administered intravenously, has been shown to reach sufficient concentrations to be a potent inhibitor of MAO-A. At recommended dosages, rasagiline, oral selegiline, and transdermal selegiline up to 6mg/day are selective for MAO-B; however, at higher dosages they have been shown to lose their selectivity. 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.	EMSAM, FURAZOLIDONE, MARPLAN, MATULANE, METAXALONE, METHYLENE BLUE, NARDIL, PARNATE, PHENELZINE SULFATE, PROCARBAZINE HCL, PROVAYBLUE, SELEGILINE HCL, TRANYLCYPROMINE SULFATE
Selected Antihistamines/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: MAOIs prolong and intensify the effects of antihistamines.(1-6) CLINICAL EFFECTS: Concurrent use of antihistamines and a MAOI may result in severe hypotension.(1-6) PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: Concurrent use of antihistamines and a MAOI is contraindicated.(1-6) DISCUSSION: MAOIs may prolong and intensify the effects of antihistamines, resulting in severe hypotension.(1-6) A case report describes a patient having cyproheptadine added to their phenelzine therapy in an attempt to relieve the patients anorgasmia. The patient began to suddenly experience visual hallucination after taking the cyproheptadine for two months. Once the medication was terminated, the hallucinations stopped occurring within 48 hours.(7) Methylene blue, when administered intravenously, has been shown to reach sufficient concentrations to be a potent inhibitor of MAO-A.(8,9)	AZILECT, EMSAM, FURAZOLIDONE, MARPLAN, MATULANE, METHYLENE BLUE, NARDIL, PARNATE, PHENELZINE SULFATE, PROCARBAZINE HCL, PROVAYBLUE, RASAGILINE MESYLATE, SELEGILINE HCL, TRANYLCYPROMINE SULFATE, XADAGO, ZELAPAR
Dihydroergotamine/Sympathomimetics 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 dihydroergotamine and sympathomimetics may result in additive or synergistic effect on peripheral blood vessels.(1) CLINICAL EFFECTS: Concurrent use of dihydroergotamine and sympathomimetics may result in increased blood pressure due to peripheral vasoconstriction.(1) PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: Dihydroergotamine is contraindicated with sympathomimetics because the combination may result in additive or synergistic elevation of blood pressure.(1) DISCUSSION: Significant elevation in blood pressure has been reported in patients treated with dihydroergotamine.(1) Sympathomimetics can be expected to have additional effects on blood pressure.	DIHYDROERGOTAMINE MESYLATE, MIGRANAL, TRUDHESA

There are 13 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
Ergot Alkaloids/Sympathomimetics SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Concurrent use of ergot alkaloids and sympathomimetics may result in additive or synergistic effect on peripheral blood vessels. CLINICAL EFFECTS: Concurrent use of ergot alkaloids and sympathomimetics may result in increased blood pressure due to peripheral vasoconstriction. PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: When possible, avoid the concurrent use of ergot alkaloids and sympathomimetics. If concurrent use is warranted, monitor blood pressure and for signs of vasoconstriction. Decreasing the dose of one or both drugs may be necessary. DISCUSSION: There have been reports of severe vasoconstriction resulting in gangrene in patients receiving intravenous ergonovine with dopamine or norepinephrine.	ERGOLOID MESYLATES, ERGOMAR, ERGOTAMINE TARTRATE, ERGOTAMINE-CAFFEINE, METHYLERGONOVINE MALEATE, METHYSERGIDE MALEATE, MIGERGOT
Selected Inhalation Anesthetic Agents/Sympathomimetics SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: The exact mechanism is unknown. The anesthetics produce conduction changes that increase impulse re-entry into the myocardial tissue.(1) The anesthetics' ability to precipitate arrhythmias is enhanced by elevated arterial blood pressure, tachycardia, hypercapnia, and/or hypoxia, events that stimulate the release of endogenous catecholamines.(1) CLINICAL EFFECTS: Concurrent use of inhalation anesthetic agents and sympathomimetics may result in ventricular arrhythmias or sudden blood pressure and heart rate increase during surgery.(2) PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: Monitor blood pressure and avoid use of sympathomimetics in patients being treated with anesthetics on the day of surgery.(2) Intravenous use of epinephrine during surgery with halothane and related halogenated general anesthetics should be strongly discouraged. When intravenous epinephrine is necessary, nitrous oxide anesthesia supplemented with ether, muscle relaxants, or opioids should be used instead of halothane.(3,4) Epinephrine may safely be used subcutaneously with the following precautions: the patient is adequately ventilated to prevent hypoxia or respiratory acidosis; the total dose of epinephrine is limited to 100 mcg/10 minute period or 300 mcg/hour in adults, 3.5 mcg/Kg in infants, 2.5 mcg/Kg in children up to two years of age, and 1.45 mcg/Kg in children over two years of age; a minimum effective concentration of anesthetic is maintained; the drugs are not co-administered in patients with hypertension or other cardiovascular disorders; and the cardiac rhythm is continuously monitored during and after injection.(3-10) If arrhythmias occur after the administration of the epinephrine, the drugs of choice are lidocaine or propranolol, depending on the type of arrhythmia.(1) DISCUSSION: Administration of epinephrine during halothane anesthesia may may lead to serious ventricular arrhythmias.(3-6,11-18) This has occurred when epinephrine was administered intravenously,(6) when it was administered with lidocaine as a dental block,(11,14) or when it was administered supraperiosteally.(5) Norepinephrine has been shown to interact with halothane in a manner similar to epinephrine.(1) In two case reports, patients were given terbutaline (0.25 to 0.35 mg) for wheezing following induction of anesthesia with halothane. One patient's heart rate increased from 68 to 100 beats/minute, and the ECG showed premature ventricular contractions and bigeminy, while the other patient developed multiple unifocal premature ventricular contractions and bigeminy. The arrhythmias resolved in both patients following lidocaine administration.(19) Although not documented, isoproterenol causes effects on the heart similar to terbutaline(20) and would probably interact with halothane in a similar manner. Other inhalation anesthetics that increase the incidence of arrhythmias with epinephrine include chloroform,(20) methoxyflurane,(20) and enflurane.(12) A similar interaction may be expected between the other inhalation anesthetics and sympathomimetics.	DESFLURANE, FORANE, ISOFLURANE, SEVOFLURANE, SUPRANE, TERRELL, ULTANE
Solid Oral Potassium Tablets/Anticholinergics SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Concentrated potassium may damage the lining of the GI tract. Anticholinergics delay gastric emptying, resulting in the potassium product remaining in the gastrointestinal tract for a longer period of time.(1-16) CLINICAL EFFECTS: Use of solid oral dosage forms of potassium in patients treated with anticholinergics may result in gastrointestinal erosions, ulcers, stenosis and bleeding.(1-16) PREDISPOSING FACTORS: Diseases or conditions which may increase risk for GI damage include: preexisting dysphagia, strictures, cardiomegaly, diabetic gastroparesis, elderly status, or insufficient oral intake to allow dilution of potassium.(1-10,21) Other drugs which may add to risk for GI damage include: nonsteroidal anti-inflammatory drugs (NSAIDs), bisphosphonates, or tetracyclines.(21) PATIENT MANAGEMENT: Regulatory agency and manufacturer recommendations regarding this interaction: - In the US, all solid oral dosage forms (including tablets and extended release capsules) of potassium are contraindicated in patients receiving anticholinergics at sufficient dosages to result in systemic effects.(2-8) Patients receiving such anticholinergic therapy should use a liquid form of potassium chloride.(2) - In Canada, solid oral potassium is contraindicated in any patient with a cause for arrest or delay in tablet/capsule passage through the gastrointestinal tract and the manufacturers recommend caution with concurrent anticholinergic medications.(1,9-10) Evaluate each patient for predisposing factors which may increase risk for GI damage. In patients with multiple risk factors for harm, consider use of liquid potassium supplements, if tolerated. For patients receiving concomitant therapy, assure any potassium dose form is taken after meals with a large glass of water or other fluid. To decrease potassium concentration in the GI tract, limit each dose to 20 meq; if more than 20 meq daily is required, give in divided doses.(2) If concurrent therapy is warranted, monitor patients receiving concurrent therapy for signs of blood loss, including decreased hemoglobin, hematocrit, fecal occult blood, and/or decreased blood pressure and promptly evaluate patients with any symptoms. Patients should be instructed to immediately report any difficulty swallowing, abdominal pain, distention, severe vomiting, or gastrointestinal bleeding. Instruct patients to report any signs and symptoms of bleeding, such as unusual bleeding from the gums or nose; unusual bruising; red or black, tarry stools; red, pink or dark brown urine; acute abdominal or joint pain and/or swelling. DISCUSSION: In clinical trials, there was a higher incidence of gastric and duodenal lesions in patients receiving a high dose of a wax-matrix controlled-release formulation with a concurrent anticholinergic agent. Some lesions were asymptomatic and not accompanied by bleeding, as shown by a lack of positive Hemoccult tests.(1-17) Several studies suggest that the incidence of gastric and duodenal lesions may be less with the microencapsulated formulation of potassium chloride.(14-17)	KLOR-CON 10, KLOR-CON 8, KLOR-CON M10, KLOR-CON M15, KLOR-CON M20, POTASSIUM CHLORIDE, POTASSIUM CITRATE ER, UROCIT-K
Solid Oral Potassium Capsules/Anticholinergics SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Concentrated potassium may damage the lining of the GI tract. Anticholinergics delay gastric emptying, resulting in the potassium product remaining in the gastrointestinal tract for a longer period of time.(1-16)) CLINICAL EFFECTS: Use of solid oral dosage forms of potassium in patients treated with anticholinergics may result in gastrointestinal erosions, ulcers, stenosis and bleeding.(1-16) PREDISPOSING FACTORS: Diseases or conditions which may increase risk for GI damage include: preexisting dysphagia, strictures, cardiomegaly, diabetic gastroparesis, elderly status, or insufficient oral intake to allow dilution of potassium.(1-10,21) Other drugs which may add to risk for GI damage include: nonsteroidal anti-inflammatory drugs (NSAIDs), bisphosphonates, or tetracyclines.(21) PATIENT MANAGEMENT: Regulatory agency and manufacturer recommendations regarding this interaction: - In the US, all solid oral dosage forms (including tablets and extended release capsules) of potassium are contraindicated in patients receiving anticholinergics at sufficient dosages to result in systemic effects.(2-8) Patients receiving such anticholinergic therapy should use a liquid form of potassium chloride.(2) - In Canada, solid oral potassium is contraindicated in any patient with a cause for arrest or delay in tablet/capsule passage through the gastrointestinal tract and the manufacturers recommend caution with concurrent anticholinergic medications.(1,9-10) Evaluate each patient for predisposing factors which may increase risk for GI damage. In patients with multiple risk factors for harm, consider use of liquid potassium supplements, if tolerated. For patients receiving concomitant therapy, assure any potassium dose form is taken after meals with a large glass of water or other fluid. To decrease potassium concentration in the GI tract, limit each dose to 20 meq; if more than 20 meq daily is required, give in divided doses.(2) If concurrent therapy is warranted, monitor patients receiving concurrent therapy for signs of blood loss, including decreased hemoglobin, hematocrit, fecal occult blood, and/or decreased blood pressure and promptly evaluate patients with any symptoms. Patients should be instructed to immediately report any difficulty swallowing, abdominal pain, distention, severe vomiting, or gastrointestinal bleeding. Instruct patients to report any signs and symptoms of bleeding, such as unusual bleeding from the gums or nose; unusual bruising; red or black, tarry stools; red, pink or dark brown urine; acute abdominal or joint pain and/or swelling. DISCUSSION: In clinical trials, there was a higher incidence of gastric and duodenal lesions in patients receiving a high dose of a wax-matrix controlled-release formulation with a concurrent anticholinergic agent. The lesions were asymptomatic and not accompanied by bleeding, as shown by a lack of positive Hemoccult tests.(1-17) Several studies suggest that the incidence of gastric and duodenal lesions may be less with the microencapsulated formulation of potassium chloride.(14-17)	POTASSIUM CHLORIDE
Mixed;Indirect Sympathomimetics/Selected MAOIs SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Catecholamine stores increased by MAOIs can be released by indirect acting sympathomimetics such as ephedrine and amphetamine. MAO inhibitors also interfere with gut and liver metabolism of direct acting sympathomimetics (e.g oral phenylephrine). CLINICAL EFFECTS: Concurrent use of MAOIs may result in potentiation of sympathomimetic effects, which may result in headaches, hypertensive crisis, toxic neurological effects, and malignant hyperpyrexia. Fatalities have occurred with combinations of sympathomimetics and MAO-A inhibitors. PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: Concurrent use of MAO-A inhibitors and sympathomimetics is contraindicated. The manufacturers of sympathomimetic agents recommend waiting 14 days after discontinuation of MAO inhibitors before initiating the sympathomimetic. Patients receiving direct or indirect acting sympathomimetics should not receive linezolid unless they are monitored for potential increases in blood pressure. Initial dosages of dopamine and epinephrine should be reduced. At recommended dosages, oral selegiline and transdermal selegiline up to 6mg/day are selective for MAO-B; however, at higher dosages they have been shown to lose their selectivity. Patients receiving higher dosages of selegiline should be considered susceptive to this interaction. DISCUSSION: Indirect acting sympathomimetic amines may cause abrupt elevation of blood pressure when administered to patients taking monoamine oxidase inhibitors, resulting in a potentially fatal hypertensive crisis. Mixed (direct and indirect) acting sympathomimetics have also been shown to interact with monoamine oxidase inhibitors depending on their degree of indirect action. The direct-acting sympathomimetics have not been reported to interact. Dopamine is metabolized by monoamine oxidase, and its pressor effect is enhanced by monoamine oxidase inhibitors. Furazolidone, an antibacterial with monoamine oxidase inhibitor action, has also been shown to interact with indirect acting sympathomimetics. Foods containing large amounts of tyramine have also been implicated in this interaction. A significant pressor response was observed in normal subjects receiving linezolid and tyramine doses of more than 100 mg. Administration of linezolid (600 mg BID for 3 days) with pseudoephedrine (60 mg q 4 hours for 2 doses) increased blood pressure by 32 mmHg. Administration of linezolid (600 mg BID for 3 days) with phenylpropanolamine (25 mg q 4 hours for 2 doses) increased blood pressure by 38 mmHg. 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.	EMSAM, LINEZOLID, LINEZOLID-0.9% NACL, LINEZOLID-D5W, SELEGILINE HCL, XADAGO, ZELAPAR, ZYVOX
Radioactive Iodide/Agents that Affect Iodide SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Many compounds can affect iodide protein binding and alter iodide pharmacokinetics and pharmacodynamics.(1) CLINICAL EFFECTS: Compounds that affect iodide pharmacokinetics and pharmacodynamics may impact the effectiveness of radioactive iodide.(1) PREDISPOSING FACTORS: Compounds that affect iodide pharmacokinetics and pharmacodynamics are expected to have the most impact during therapy using radioactive iodide. Diagnostic procedures would be expected to be impacted less. PATIENT MANAGEMENT: Discuss the use of agents that affect iodide pharmacokinetics and pharmacodynamics with the patient's oncologist.(1) Because indocyanine green contains sodium iodide, the iodine-binding capacity of thyroid tissue may be reduced for at least one week following administration. Do not perform radioactive iodine uptake studies for at least one week following administration of indocyanine green.(2) The manufacturer of iopamidol states administration may interfere with thyroid uptake of radioactive iodine and decrease therapeutic and diagnostic efficacy. Avoid thyroid therapy or testing for up to 6 weeks post administration of iopamidol.(3) DISCUSSION: Many agents interact with radioactive iodine. The average duration of effect is: anticoagulants - 1 week antihistamines - 1 week anti-thyroid drugs, e.g: carbimazole, methimazole, propylthiouracil - 3-5 days corticosteroids - 1 week iodide-containing medications, e.g: amiodarone - 1-6 months expectorants - 2 weeks Lugol solution - 3 weeks saturated solution of potassium iodine - 3 weeks vitamins - 10-14 days iodide-containing X-ray contrast agents - up to 1 year lithium - 4 weeks phenylbutazone - 1-2 weeks sulfonamides - 1 week thyroid hormones (natural or synthetic), e.g.: thyroxine - 4 weeks tri-iodothyronine - 2 weeks tolbutamide - 1 week topical iodide - 1-9 months (1)	ADREVIEW, JEANATOPE, MEGATOPE, SODIUM IODIDE I-123
Selected Direct-Acting Sympathomimetics/Tricyclic Compounds SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Unknown. However, it is speculated that direct-acting sympathomimetic amines have an enhanced effect due to tricyclic blockage of norepinephrine reuptake. CLINICAL EFFECTS: Increased effect of direct acting sympathomimetics. PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: Consider avoiding the concurrent use of direct-acting sympathomimetics and tricyclic compounds. If concurrent use of direct-acting sympathomimetics and tricyclic compounds is warranted, the initial dose of the sympathomimetic should be lowered and the patient should be monitored for adverse cardiovascular effects. Use of tricyclic compounds and other sympathomimetics should be approached with caution. DISCUSSION: Epinephrine and other direct-acting sympathomimetic amines exert enhanced cardiovascular effects (e.g., arrhythmias, hypertension, and tachycardia) in individuals concurrently receiving or previously treated with tricyclic antidepressants. Other direct and mixed acting sympathomimetic amines have also been reported to interact with tricyclic antidepressants. These include norepinephrine, phenylephrine, dopamine, and methoxamine. Protriptyline, amitriptyline, and desipramine have also been reported to interact with direct-acting sympathomimetics.	AMITRIPTYLINE HCL, AMOXAPINE, ANAFRANIL, CHLORDIAZEPOXIDE-AMITRIPTYLINE, CLOMIPRAMINE HCL, DESIPRAMINE HCL, DOXEPIN HCL, IMIPRAMINE HCL, IMIPRAMINE PAMOATE, NORPRAMIN, NORTRIPTYLINE HCL, PAMELOR, PERPHENAZINE-AMITRIPTYLINE, PROTRIPTYLINE HCL, SILENOR, TRIMIPRAMINE MALEATE
Iobenguane I 123/Agents that Affect Catecholamines SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Many compounds that reduce catecholamine uptake or that deplete catecholamine stores may interfere with iobenguane uptake into cells.(1) CLINICAL EFFECTS: Compounds that reduce catecholamine uptake or that deplete catecholamine stores may interfere with imaging completed with iobenguane.(1) PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: Discuss the use of agents that affect catecholamines. Discontinue drugs that reduce catecholamine uptake or deplete catecholamine stores prior to imaging with iobenguane. Before imaging with iobenguane, discontinue agents that affect catecholamines for at least 5 biological half-lives, as clinically tolerated.(1) DISCUSSION: Many agents may reduce catecholamine uptake or deplete catecholamine stores.(1) Examples include: - CNS stimulants or amphetamines (e.g. cocaine, methylphenidate, dextroamphetamine) - norepinephrine and dopamine reuptake inhibitors (e.g. phentermine) - norepinephrine and serotonin reuptake inhibitors (e.g. tramadol) - monoamine oxidase inhibitors (e.g. phenelzine, linezolid) - central monoamine depleting drugs (e.g. reserpine) - non-select beta adrenergic blocking drugs (e.g. labetalol) - alpha agonists or alpha/beta agonists (e.g. pseudoephedrine, phenylephrine, ephedrine, phenylpropanolamine, naphazoline) - tricyclic antidepressants or norepinephrine reuptake inhibitors (e.g. amitriptyline, bupropion, duloxetine, mirtazapine, venlafaxine) - botanicals that may inhibit reuptake of norepinephrine, serotonin or dopamine (e.g. ephedra, ma huang, St. John's Wort, yohimbine)	ADREVIEW
Clozapine/Anticholinergics SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Clozapine has potent anticholinergic properties and inhibits serotonin receptors, including 5-HT3.(1-4) Both of these properties may cause inhibition of gastrointestinal (GI) smooth muscle contraction, resulting in decreased peristalsis.(3,4) These effects may be compounded by concurrent use of anticholinergic agents.(1-6) CLINICAL EFFECTS: Concurrent use of clozapine with other anticholinergic agents may increase the risk of constipation (common) and serious bowel complications (uncommon), including complete bowel obstruction, fecal impaction, paralytic ileus and intestinal ischemia or infarction.(1-6) PREDISPOSING FACTORS: The risk for serious bowel complications is higher with increasing age, higher frequency of constipation, and in patients on higher doses of clozapine or multiple anticholinergic agents.(1,5) PATIENT MANAGEMENT: Avoid the use of other anticholinergic agents with clozapine.(1-6) If concurrent use is necessary, evaluate the patient's bowel function regularly. Monitor for symptoms of constipation and GI hypomotility, including having bowel movements less than three times weekly or less than usual, difficulty having a bowel movement or passing gas, nausea, vomiting, and abdominal pain or distention.(2) Consider a prophylactic laxative in those with a history of constipation or bowel obstruction.(2) Review patient medication list for other anticholinergic agents. When possible, decrease the dosage or number of prescribed anticholinergic agents, particularly in the elderly. Counsel the patient about the importance of maintaining adequate hydration. Encourage regular exercise and eating a high-fiber diet.(2) DISCUSSION: In a prospective cohort study of 26,720 schizophrenic patients in the Danish Central Psychiatric Research Registry, the odds ratio (OR) for ileus was 1.99 with clozapine and 1.48 with anticholinergics. The OR for fatal ileus was 6.73 with clozapine and 5.88 with anticholinergics. Use of anticholinergics with 1st generation antipsychotics (FGA) increased the risk of ileus compare to FGA alone, but this analysis was not done with clozapine.(5) A retrospective cohort study of 24,970 schizophrenic patients from the Taiwanese National Health Insurance Research Database found that the hazard ratio (HR) for clozapine-induced constipation increased from 1.64 when clozapine is used alone, to 2.15 when used concomitantly with anticholinergics. However, there was no significant difference in the HR for ileus when clozapine is used with and without anticholinergics (1.95 and 2.02, respectively).(6) In the French Pharmacovigilance Database, 7 of 38 cases of antipsychotic-associated ischemic colitis or intestinal necrosis involved clozapine, and 5 of these cases involved use of concomitant anticholinergic agents. Three patients died, one of whom was on concomitant anticholinergics.(3) In a case series, 4 of 9 cases of fatal clozapine-associated GI dysfunction involved concurrent anticholinergic agents.(4)	CLOZAPINE, CLOZAPINE ODT, CLOZARIL, VERSACLOZ
Eluxadoline/Anticholinergics; Opioids SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Eluxadoline is a mixed mu-opioid and kappa-opioid agonist and delta-opioid antagonist and may alter or slow down gastrointestinal transit.(1) CLINICAL EFFECTS: Constipation related adverse events that sometimes required hospitalization have been reported, including the development of intestinal obstruction, intestinal perforation, and fecal impaction.(1) PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: Avoid use with other drugs that may cause constipation. If concurrent use is necessary, evaluate the patient's bowel function regularly. Monitor for symptoms of constipation and GI hypomotility, including having bowel movements less than three times weekly or less than usual, difficulty having a bowel movement or passing gas, nausea, vomiting, and abdominal pain or distention.(1) Instruct patients to stop eluxadoline and immediately contact their healthcare provider if they experience severe constipation. Loperamide may be used occasionally for acute management of severe diarrhea, but must be discontinued if constipation develops.(1) DISCUSSION: In phase 3 clinical trials, constipation was the most commonly reported adverse reaction (8%). Approximately 50% of constipation events occurred within the first 2 weeks of treatment while the majority occurred within the first 3 months of therapy. Rates of severe constipation were less than 1% in patients receiving eluxadoline doses of 75 mg and 100 mg.(1)	VIBERZI
Mixed;Indirect Sympathomimetics/Rasagiline SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Catecholamine stores increased by MAOIs can be released by indirect acting sympathomimetics such as ephedrine and amphetamine. MAO inhibitors also interfere with gut and liver metabolism of direct acting sympathomimetics (e.g oral phenylephrine). CLINICAL EFFECTS: Concurrent use of MAOIs may result in potentiation of sympathomimetic effects, which may result in headaches, hypertensive crisis, toxic neurological effects, and malignant hyperpyrexia. Hypertensive crisis has been reported in patients taking recommended doses of rasagiline with sympathomimetic agents. PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: At recommended dosages, rasagiline is selective for MAO-B; however, at higher dosages it has been shown to lose its selectivity. Patients receiving higher dosages of rasagiline should be considered susceptive to this interaction. Concurrent use should be approached with caution. DISCUSSION: Indirect acting sympathomimetic amines may cause abrupt elevation of blood pressure when administered to patients taking monoamine oxidase inhibitors, resulting in a potentially fatal hypertensive crisis. Mixed (direct and indirect) acting sympathomimetics have also been shown to interact with monoamine oxidase inhibitors depending on their degree of indirect action. The direct-acting sympathomimetics have not been reported to interact. Dopamine is metabolized by monoamine oxidase, and its pressor effect is enhanced by monoamine oxidase inhibitors.	AZILECT, RASAGILINE MESYLATE
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
Sodium Iodide I 131/Agents that Affect Iodide SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Many compounds can affect iodide protein binding and alter iodide pharmacokinetics and pharmacodynamics.(1,2) CLINICAL EFFECTS: Compounds that affect iodide pharmacokinetics and pharmacodynamics may impact the effectiveness of radioactive iodide.(1,2) PREDISPOSING FACTORS: Compounds that affect iodide pharmacokinetics and pharmacodynamics are expected to have the most impact during therapy using radioactive iodide. Diagnostic procedures would be expected to be impacted less. PATIENT MANAGEMENT: Discuss the use of agents that affect iodide pharmacokinetics and pharmacodynamics with the patient's oncologist.(1,2) Because indocyanine green contains sodium iodide, the iodine-binding capacity of thyroid tissue may be reduced for at least one week following administration. Do not perform radioactive iodine uptake studies for at least one week following administration of indocyanine green.(3) The manufacturer of iopamidol states administration may interfere with thyroid uptake of radioactive iodine and decrease therapeutic and diagnostic efficacy. Avoid thyroid therapy or testing for up to 6 weeks post administration of iopamidol.(4) DISCUSSION: Many agents interact with radioactive iodine. The average duration of effect is: anticoagulants - 1 week antihistamines - 1 week anti-thyroid drugs, e.g: carbimazole, methimazole, propylthiouracil - 3-5 days corticosteroids - 1 week iodide-containing medications, e.g: amiodarone - 1-6 months expectorants - 2 weeks Lugol solution - 3 weeks saturated solution of potassium iodine - 3 weeks vitamins - 10-14 days iodide-containing X-ray contrast agents - up to 1 year lithium - 4 weeks phenylbutazone - 1-2 weeks sulfonamides - 1 week thyroid hormones (natural or synthetic), e.g.: thyroxine - 4 weeks tri-iodothyronine - 2 weeks tolbutamide - 1 week topical iodide - 1-9 months (1,2)	HICON, SODIUM IODIDE I-131

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
Sympathomimetics (Direct, Mixed-Acting)/Guanethidine SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Direct or mixed-acting sympathomimetics 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 direct or mixed-acting sympathomimetic. 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. DISCUSSION: Documentation supports routine monitoring of this interaction. It should be noted that this interaction can occur quickly.	GUANETHIDINE HEMISULFATE
Sympathomimetics/Rauwolfia Alkaloids SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Reserpine depletes catecholamine stores within the peripheral vascular adrenergic nerve endings, thus indirect acting sympathomimetics are unable to trigger the release of catecholamines. The reserpine-induced catecholamine release increases sensitivity to the effects of direct acting sympathomimetics. CLINICAL EFFECTS: Increased effects of direct acting sympathomimetics. Decreased effects of indirect acting sympathomimetics. Mixed acting sympathomimetics will show effects based on the predominance of either direct or indirect activity. PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: If these agents are administered concurrently, monitor blood pressure. The dose of the sympathomimetic may need to be adjusted. DISCUSSION: This interaction has been well documented in animal studies and human case reports have confirmed the interaction. Reserpine has been shown to decrease the response to epinephrine administered for hypotension. Reserpine has also been shown to decrease the effectiveness of ophthalmic epinephrine, a direct acting sympathomimetic. Ophthalmic phenylephrine has been shown to decrease the hypotensive effects of reserpine.	RESERPINE
Sympathomimetics (Direct, Mixed-Acting)/Methyldopa SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Unknown. CLINICAL EFFECTS: The pressor response to sympathomimetics may be increased. PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: Start with low doses of sympathomimetics and monitor blood pressure of patients during concurrent administration of sympathomimetics and methyldopa. DISCUSSION: The pressor response to sympathomimetics has been reported to be increased during methyldopa administration. In addition to increased duration of pressor response, severe hypertension has been reported.	METHYLDOPA, METHYLDOPA-HYDROCHLOROTHIAZIDE, METHYLDOPATE HCL
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, PHENTERMINE-TOPIRAMATE ER, QSYMIA, TOPAMAX, TOPIRAMATE, TOPIRAMATE ER, TOPIRAMATE ER SPRINKLE, TROKENDI XR

The following contraindication information is available for POLY HIST FORTE (doxylamine succinate/phenylephrine hcl):

Overview
Contraindicated
Severe
Moderate

Drug contraindication overview.

Doxylamine succinate is contraindicated in patients with known hypersensitivity to doxylamine, other ethanolamine derivative antihistamines, or any ingredient in the formulation. Doxylamine in fixed combination with pyridoxine is contraindicated in patients receiving monoamine oxidase (MAO) inhibitors.

There are 1 contraindications. Absolute contraindication.

Contraindication List
Severe uncontrolled hypertension

There are 9 severe contraindications. Adequate patient monitoring is recommended for safer drug use.

Severe List
Angle-closure glaucoma
Benign prostatic hyperplasia
Bladder outflow obstruction
Chronic idiopathic constipation
Coronary artery disease
Hypertension
Hyperthyroidism
Stenosing peptic ulcer
Urinary retention

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
Chronic heart failure
Coronary artery disease
Hypertension
Hyperthyroidism
Ocular hypertension
Pyloroduodenal obstruction
Seizure disorder

The following adverse reaction information is available for POLY HIST FORTE (doxylamine succinate/phenylephrine hcl):

Overview
Severe
Less Severe

Adverse reaction overview.

No enhanced Common Adverse Effects information available for this drug.

There are 17 severe adverse reactions.

More Frequent	Less Frequent
None.	None.

Rare/Very Rare
Anaphylaxis Blood dyscrasias Cardiac arrhythmia Dizziness Extrasystoles Hallucinations Headache disorder Hemolytic anemia Hyperhidrosis Hypersensitivity drug reaction Hypotension Insomnia Nervousness Pallor Seizure disorder Tachycardia Tremor

There are 52 less severe adverse reactions.

More Frequent	Less Frequent
Anticholinergic toxicity Dizziness Drowsy Thick bronchial secretions	Muscle weakness Sedation

Rare/Very Rare
Abdominal distension Accidental fall Acute abdominal pain Acute cognitive impairment Agitation Anorexia Ataxia Blurred vision Chest discomfort Chills Constipation Diarrhea Diplopia Dry nose Dry throat Dyspnea Dysuria Euphoria Excitement Fatigue Headache disorder Hyperhidrosis Insomnia Irritability Maculopapular rash Malaise Migraine Nausea Nervousness Nightmares Palpitations Paresthesia Pruritus of skin Skin photosensitivity Skin rash Symptoms of anxiety Tachycardia Tinnitus Tremor Urinary retention Urticaria Vertigo Visual changes Vomiting Wheezing Xerostomia

Rare/Very Rare

Abdominal distension
Accidental fall
Acute abdominal pain
Acute cognitive impairment
Agitation
Anorexia
Ataxia
Blurred vision
Chest discomfort
Chills
Constipation
Diarrhea
Diplopia
Dry nose
Dry throat
Dyspnea
Dysuria
Euphoria
Excitement
Fatigue
Headache disorder
Hyperhidrosis
Insomnia
Irritability
Maculopapular rash
Malaise
Migraine
Nausea
Nervousness
Nightmares
Palpitations
Paresthesia
Pruritus of skin
Skin photosensitivity
Skin rash
Symptoms of anxiety
Tachycardia
Tinnitus
Tremor
Urinary retention
Urticaria
Vertigo
Visual changes
Vomiting
Wheezing
Xerostomia

The following precautions are available for POLY HIST FORTE (doxylamine succinate/phenylephrine hcl):

Pediatric
Pregnant
Lactation
Geriatric

No enhanced Pediatric Use information available for this drug.

Contraindicated

None

Severe Precaution

None

Management or Monitoring Precaution

None

Doxylamine succinate in fixed combination with pyridoxine hydrochloride is intended for use in the management of nausea and vomiting of pregnancy. Numerous epidemiologic studies (including cohort studies, case-control studies, and meta-analyses) have been performed to investigate possible teratogenic effects of doxylamine in fixed combination with pyridoxine in pregnant women. A meta-analysis of 16 cohort and 11 case-control studies published between 1963 and 1991 reported no increased risk for malformations from first trimester exposures to doxylamine succinate and pyridoxine hydrochloride in fixed combination, with or without dicyclomine hydrochloride (a drug included in a combination product that was previously commercially available for nausea and vomiting of pregnancy).

Another meta-analysis of 12 cohort and 5 case-control studies published between 1963 and 1985 reported no clinically important associations between fetal abnormalities and first trimester exposure to doxylamine succinate and pyridoxine hydrochloride with or without dicyclomine hydrochloride. A reanalysis of data from another meta-analysis supporting the safety of doxylamine during pregnancy found that the strength of the data had been overstated, both in terms of the numbers of patients exposed to doxylamine succinate and the reported odds ratio, which suggested a potential protective effect of antihistamines with regard to fetal malformations. However, the reanalysis did not find evidence of an increased risk of fetal malformations associated with doxylamine use.

Historically, there was considerable controversy regarding the teratogenic potential, if any, of doxylamine; however, after evaluating extensive data and information concerning the possible teratogenicity of the drug, FDA concluded that it is unlikely that doxylamine is teratogenic. FDA recognized, however, that despite the large number of pregnancies evaluated to date the possibility that doxylamine may be weakly teratogenic cannot be excluded. Doxylamine was commercially available in the US for the treatment of nausea and vomiting associated with pregnancy in combination with dicyclomine and pyridoxine until 1976, and then in combination with only pyridoxine until 1983 when the manufacturer voluntarily discontinued manufacturing and distributing the combination.

FDA stated that the removal of products containing doxylamine and pyridoxine that previously were commercially available for the management of nausea and vomiting of pregnancy was not for reasons of safety or effectiveness. Most epidemiologic studies (case-control and cohort) in which fixed combinations of doxylamine and pyridoxine with or without dicyclomine were used during pregnancy indicate that an association between use of these combinations and adverse fetal effects does not appear to exist. In a few studies, a weak association between use of the fixed combinations during pregnancy and specific fetal abnormalities (e.g., pyloric stenosis, cardiac defects, oral clefts) was reported, but a causal relationship with the drugs was not established and these findings have not been confirmed by many other studies.

Women considering self-medication with doxylamine during pregnancy should consult a health professional for advice regarding the relative risks and benefits of such therapy. Most reproduction studies in various animal species using doxylamine and pyridoxine alone or in fixed combination have not revealed evidence of harm to the fetus. Studies in rats and mice using doxylamine succinate dosages up to 125 times the maximum human dosage did not reveal evidence of observable congenital abnormalities, but wavy ribs and diaphragmatic hernias occurred in rats at dosages 125-375 times the maximum human dosage; an overall increase in fetal wastage, varying from zero to threefold, occurred in most rodents receiving dosages 125 or more times greater than the maximum human dosage.

Once daily administration of doxylamine succinate and pyridoxine hydrochloride in pregnant rats during organogenesis (gestational day 6-15) resulted in increased fetal resorptions, decreased fetal body weight, and increased skeletal variations with reduced ossification at dosages 60-100 times the highest clinical dosage based on body surface area. In a study in pregnant cynomolgus monkeys receiving doxylamine succinate and pyridoxine hydrochloride once daily during organogenesis (gestational day 22-50) at dosages up to 3.2 times the highest proposed clinical dosage based on body surface area, there were no observed malformations and no evidence of embryo, fetal, or maternal toxicity.

In another study in pregnant cynomolgus and rhesus monkeys and baboons receiving doxylamine succinate and pyridoxine hydrochloride at dosages 0.5-20 times higher than the clinical dosage based on body surface area, ventricular septal defects were observed in preterm (gestational day 100) fetuses; no relationship between dosage and incidence of ventricular septal defects was observed, and no ventricular septal defects were observed in infant monkeys at term. In addition, no ventricular septal defects were observed at gestational day 100 in cynomolgus monkeys administered the combination of doxylamine succinate and pyridoxine hydrochloride for 4-day periods between 22 and 41 days of gestation.

In a small study in monkeys receiving a fixed combination of doxylamine succinate and pyridoxine hydrochloride throughout fetal organogenesis at dosages 10-20 times the maximum human dosage, intraventricular septal defects were present in 4 of 7 fetuses delivered on day 100 of gestation (full-term gestation is about 160 days), while 2 fetuses aborted on the 46th and 56th day of gestation appeared to be developing normally and 3 other fetuses allowed to develop to term were normal. The importance of septal defects in these monkeys is not known, since an opening in the septum is usually present early during fetal development in monkeys. In other studies in monkeys receiving the fixed combination for shorter periods of time, there was no evidence of fetal toxicity.

It is not known whether phenylephrine hydrochloride can cause fetal harm when administered to pregnant women; the drug should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Animal studies suggest a potential for adverse cardiovascular effects to the fetus if the drug is administered IV during pregnancy. Administration of phenylephrine to patients in late pregnancy or labor may cause fetal anoxia and bradycardia by increasing contractility of the uterus and decreasing uterine blood flow.

In studies of IV phenylephrine in pregnant women undergoing cesarean delivery with neuraxial anesthesia, common adverse effects reported in the mother included nausea and vomiting, bradycardia, reactive hypertension, and transient arrhythmias. The drug did not appear to affect neonatal Apgar scores or umbilical artery blood-gas status. If a vasopressor is used in conjunction with oxytocic drugs, the vasopressor effect is potentiated and may result in potentially serious adverse effects. (See Drug Interactions: Oxytocic Drugs.)

Doxylamine succinate is expected to be distributed into human milk, because of its low molecular weight. Adverse effects (e.g., excitement, irritability, and sedation) have been reported in infants presumably exposed to doxylamine through human milk. Infants with apnea or other respiratory syndromes may be particularly vulnerable to the sedative effects of doxylamine.

Because of the potential for serious adverse reactions to antihistamines in nursing infants, a decision should be made whether to discontinue nursing or doxylamine, taking into account the importance of the drug to the woman. The manufacturer of doxylamine/pyridoxine in fixed combination states that this preparation should notbe used in nursing women. It is not known whether phenylephrine is distributed into human milk following parenteral administration. The drug should be used with caution in nursing women.

No enhanced Geriatric Use information available for this drug.

The following icd codes are available for POLY HIST FORTE (doxylamine succinate/phenylephrine hcl)'s list of indications:

Allergic conjunctivitis
H10.1	Acute atopic conjunctivitis
H10.10	Acute atopic conjunctivitis, unspecified eye
H10.11	Acute atopic conjunctivitis, right eye
H10.12	Acute atopic conjunctivitis, left eye
H10.13	Acute atopic conjunctivitis, bilateral
H10.44	Vernal conjunctivitis
H10.45	Other chronic allergic conjunctivitis
H16.26	Vernal keratoconjunctivitis, with limbar and corneal involvement
H16.261	Vernal keratoconjunctivitis, with limbar and corneal involvement, right eye
H16.262	Vernal keratoconjunctivitis, with limbar and corneal involvement, left eye
H16.263	Vernal keratoconjunctivitis, with limbar and corneal involvement, bilateral
H16.269	Vernal keratoconjunctivitis, with limbar and corneal involvement, unspecified eye
Allergic rhinitis
J30.1	Allergic rhinitis due to pollen
J30.2	Other seasonal allergic rhinitis
J30.5	Allergic rhinitis due to food
J30.8	Other allergic rhinitis
J30.81	Allergic rhinitis due to animal (cat) (dog) hair and dander
J30.89	Other allergic rhinitis
J30.9	Allergic rhinitis, unspecified
Cold symptoms
J00	Acute nasopharyngitis [common cold]
Nasal congestion
R09.81	Nasal congestion
Perennial allergic rhinitis
J31.0	Chronic rhinitis
Rhinorrhea
R09.82	Postnasal drip
Seasonal allergic rhinitis
J30.1	Allergic rhinitis due to pollen
J30.2	Other seasonal allergic rhinitis
Sneezing
R06.7	Sneezing
Vasomotor rhinitis
J30.0	Vasomotor rhinitis