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Chlorpheniramine, Phenylephrine, and Dextromethorphan

Medically reviewed by Drugs.com. Last updated on May 19, 2020.

Pronunciation

(klor fen IR a meen, fen il EF rin, & deks troe meth OR fan)

Index Terms

  • Dextromethorphan, Chlorpheniramine, and Phenylephrine
  • Dm/Phenyleph/Chlorpheniramine
  • Phenylephrine, Chlorpheniramine, and Dextromethorphan

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = discontinued product.

Liquid, oral:

De-Chlor DM: Chlorpheniramine maleate 2 mg, phenylephrine hydrochloride 10 mg, and dextromethorphan hydrobromide 15 mg per 5 mL (473 mL) [dye free, ethanol free, sugar free; contains propylene glycol; strawberry flavor]

Ed A-Hist DM: Chlorpheniramine maleate 4 mg, phenylephrine hydrochloride 10 mg, and dextromethorphan hydrobromide 15 mg per 5 mL (473 mL) [gluten free, sugar free; contains propylene glycol; banana flavor]

Father John's® Plus: Chlorpheniramine maleate 2 mg, phenylephrine hydrochloride 5 mg, and dextromethorphan hydrobromide 5 mg per 15 mL (118 mL) [ethanol free]

NoHist DM: Chlorpheniramine maleate 4 mg, phenylephrine hydrochloride 10 mg, and dextromethorphan hydrobromide 15 mg per 5 mL (473 mL) [dye free, ethanol free, sugar free; contains propylene glycol; grape flavor]

Norel CS: Chlorpheniramine maleate 4 mg, phenylephrine hydrochloride 10 mg, and dextromethorphan hydrobromide 12.5 mg per 5 mL (473 mL [DSC]) [dye free, ethanol free, sugar free; contains propylene glycol; grape flavor]

Liquid, oral [drops]:

nasohist™ DM pediatric: Chlorpheniramine maleate 1 mg, phenylephrine hydrochloride 2 mg, and dextromethorphan hydrobromide 3 mg per 1 mL (30 mL [DSC]) [dye free, ethanol free, sugar free; contains propylene glycol; orange-vanilla flavor]

Virdec DM: Chlorpheniramine maleate 1 mg, phenylephrine hydrochloride 3.5 mg, and dextromethorphan hydrobromide 3 mg per 1 mL (30 mL [DSC]) [ethanol free, gluten free, sugar free; contains propylene glycol; grape flavor]

Tablet, oral:

Ed A-Hist: Chlorpheniramine maleate 4 mg, phenylephrine hydrochloride 10 mg, and dextromethorphan hydrobromide 10 mg

Maxichlor PEH DM: Chlorpheniramine mlaeate 4 mg, phenylephrine hydrochloride 10 mg, dextromethorphan hydrobromide 18 mg

Brand Names: U.S.

  • De-Chlor DM [OTC]
  • Ed A-Hist DM [OTC]
  • Father John's Plus [OTC]
  • Maxichlor PEH DM [OTC]
  • NoHist DM [OTC]
  • Norel CS [OTC] [DSC]
  • Virdec DM [OTC] [DSC]

Pharmacologic Category

  • Alkylamine Derivative
  • Alpha-Adrenergic Agonist
  • Antitussive
  • Decongestant
  • Histamine H1 Antagonist
  • Histamine H1 Antagonist, First Generation

Use: Labeled Indications

Cough and upper respiratory symptoms: Temporary relief of symptoms (runny nose, sneezing, itchy nose or throat, itchy/watery eyes, cough due to minor throat and bronchial irritation, nasal congestion, nasal passages swelling) associated with the common cold, hay fever (allergic rhinitis), or other upper respiratory allergies.

Contraindications

Do not use to sedate or make a child sleep; with or within 14 days of stopping a monoamine oxidase inhibitor (MAO) inhibitor therapy.

Dosing: Adult

Note: All dosing is presented in terms of chlorpheniramine maleate/phenylephrine hydrochloride/dextromethorphan hydrobromide.

Cough and upper respiratory symptoms: Oral: Dosing may vary by product; consult specific product labeling.

Liquid:

Chlorpheniramine 2 mg/phenylephrine 5 mg/dextromethorphan 5 mg per 15 mL: 30 mL every 4 hours (maximum: 180 mL/24 hours)

Chlorpheniramine 2 to 4 mg/phenylephrine 5 to 10 mg/dextromethorphan 12.5 to 15 mg per 5 mL: 5 mL every 4 to 6 hours (maximum: 30 mL/24 hours)

Tablet:

Chlorpheniramine 4 mg/phenylephrine 10 mg/dextromethorphan 10 mg: One tablet every 4 hours (maximum: 6 tablets/24 hours)

Chlorpheniramine 4 mg/phenylephrine 10 mg/dextromethorphan 18 mg: One tablet every 4 hours (maximum: 6 tablets/24 hours)

Dosing: Geriatric

Avoid use (Beers Criteria [AGS 2019]).

Dosing: Pediatric

Note: Multiple concentrations of oral liquid formulations exist; close attention must be paid to the concentration when ordering or administering. Safety and efficacy for the use of cough and cold products in infants and young children is limited; the AAP warns against the use of these products for respiratory illnesses in infants and young children; the FDA does not recommend OTC use in infants and children <2 years of age due to the risk of serious and life-threatening adverse effects (including death) and recommends to use with caution in pediatric patients ≥2 years of age (AAP 2018; FDA 2017).

Cough and upper respiratory symptoms: Dosing may vary by product; consult specific product labeling.

Liquid:

Chlorpheniramine 4 mg/phenylephrine 10 mg/dextromethorphan 15 mg per 5 mL (eg, Ed A-Hist DM liquid, NoHist DM): Oral:

Children 6 to <12 years: 2.5 mL every 4 hours as needed. Maximum daily dose: 15 mL/24 hours.

Children ≥12 years and Adolescents: 5 mL every 4 hours as needed. Maximum daily dose: 30 mL/24 hours.

Chlorpheniramine 2 mg/phenylephrine 5 mg/dextromethorphan 5 mg per 15 mL (eg, Father John's Medicine Plus): Oral: Children ≥12 years and Adolescents: 30 mL every 4 hours as needed. Maximum daily dose: 180 mL/24 hours.

Tablets:

Chlorpheniramine 4 mg/phenylephrine 10 mg/dextromethorphan 10 mg per tablet (eg, Ed Hist-A DM tablets): Oral:

Children 6 to <12 years: 1/2 tablet every 4 hours as needed. Maximum daily dose: 3 tablets/24 hours.

Children ≥12 years and Adolescents: 1 tablet every 4 hours as needed. Maximum daily dose: 6 tablets/24 hours.

Chlorpheniramine 4 mg/phenylephrine 10 mg/dextromethorphan 18 mg per tablet (eg, Maxichlor): Oral:

Children 6 to <12 years: 1/2 tablet every 4 hours as needed. Maximum daily dose: 3 tablets/24 hours.

Children ≥12 years and Adolescents: 1 tablet every 4 hours as needed. Maximum daily dose: 6 tablets/24 hours.

Storage

Store at room temperature.

Drug Interactions

Acetaminophen: May increase the serum concentration of Phenylephrine (Systemic). Monitor therapy

Acetylcholinesterase Inhibitors: Anticholinergic Agents may diminish the therapeutic effect of Acetylcholinesterase Inhibitors. Acetylcholinesterase Inhibitors may diminish the therapeutic effect of Anticholinergic Agents. Monitor therapy

Aclidinium: May enhance the anticholinergic effect of Anticholinergic Agents. Avoid combination

Ajmaline: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

Alcohol (Ethyl): CNS Depressants may enhance the CNS depressant effect of Alcohol (Ethyl). Monitor therapy

Alizapride: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Alpha1-Blockers: May diminish the vasoconstricting effect of Alpha1-Agonists. Similarly, Alpha1-Agonists may antagonize Alpha1-Blocker vasodilation. Monitor therapy

Amantadine: May enhance the anticholinergic effect of Anticholinergic Agents. Monitor therapy

Amezinium: Antihistamines may enhance the stimulatory effect of Amezinium. Monitor therapy

Amphetamines: May diminish the sedative effect of Antihistamines. Monitor therapy

Anticholinergic Agents: May enhance the adverse/toxic effect of other Anticholinergic Agents. Monitor therapy

AtoMOXetine: May enhance the hypertensive effect of Sympathomimetics. AtoMOXetine may enhance the tachycardic effect of Sympathomimetics. Monitor therapy

Azelastine (Nasal): CNS Depressants may enhance the CNS depressant effect of Azelastine (Nasal). Avoid combination

Benzylpenicilloyl Polylysine: Antihistamines may diminish the diagnostic effect of Benzylpenicilloyl Polylysine. Management: Suspend systemic H1 antagonists for benzylpenicilloyl-polylysine skin testing and delay testing until systemic antihistaminic effects have dissipated. A histamine skin test may be used to assess persistent antihistaminic effects. Consider therapy modification

Benzylpenicilloyl Polylysine: Alpha1-Agonists may diminish the diagnostic effect of Benzylpenicilloyl Polylysine. Management: Consider use of a histamine skin test as a positive control to assess a patient's ability to mount a wheal and flare response. Consider therapy modification

Betahistine: Antihistamines may diminish the therapeutic effect of Betahistine. Monitor therapy

Blonanserin: CNS Depressants may enhance the CNS depressant effect of Blonanserin. Management: Use caution if coadministering blonanserin and CNS depressants; dose reduction of the other CNS depressant may be required. Strong CNS depressants should not be coadministered with blonanserin. Consider therapy modification

Botulinum Toxin-Containing Products: May enhance the anticholinergic effect of Anticholinergic Agents. Monitor therapy

Brexanolone: CNS Depressants may enhance the CNS depressant effect of Brexanolone. Monitor therapy

Brimonidine (Topical): May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Bromopride: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Bromperidol: May enhance the CNS depressant effect of CNS Depressants. Avoid combination

Buprenorphine: CNS Depressants may enhance the CNS depressant effect of Buprenorphine. Management: Consider reduced doses of other CNS depressants, and avoiding such drugs in patients at high risk of buprenorphine overuse/self-injection. Initiate buprenorphine at lower doses in patients already receiving CNS depressants. Consider therapy modification

Cannabidiol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Cannabis: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Chloral Betaine: May enhance the adverse/toxic effect of Anticholinergic Agents. Monitor therapy

Chlormethiazole: May enhance the CNS depressant effect of CNS Depressants. Management: Monitor closely for evidence of excessive CNS depression. The chlormethiazole labeling states that an appropriately reduced dose should be used if such a combination must be used. Consider therapy modification

Chloroprocaine: May enhance the hypertensive effect of Phenylephrine (Systemic). Monitor therapy

Chlorphenesin Carbamate: May enhance the adverse/toxic effect of CNS Depressants. Monitor therapy

Cimetropium: Anticholinergic Agents may enhance the anticholinergic effect of Cimetropium. Avoid combination

CloZAPine: Anticholinergic Agents may enhance the constipating effect of CloZAPine. Management: Consider alternatives to this combination whenever possible. If combined, monitor closely for signs and symptoms of gastrointestinal hypomotility and consider prophylactic laxative treatment. Consider therapy modification

CNS Depressants: May enhance the adverse/toxic effect of other CNS Depressants. Monitor therapy

Cobicistat: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

Cocaine (Topical): May enhance the hypertensive effect of Sympathomimetics. Management: Consider alternatives to use of this combination when possible. Monitor closely for substantially increased blood pressure or heart rate and for any evidence of myocardial ischemia with concurrent use. Consider therapy modification

CYP2D6 Inhibitors (Moderate): May increase the serum concentration of Dextromethorphan. Exceptions: DULoxetine. Monitor therapy

CYP2D6 Inhibitors (Strong): May increase the serum concentration of Chlorpheniramine. Monitor therapy

CYP2D6 Inhibitors (Strong): May increase the serum concentration of Dextromethorphan. Monitor therapy

Dimethindene (Topical): May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Disulfiram: May enhance the adverse/toxic effect of Products Containing Ethanol. Management: Do not use disulfiram with dosage forms that contain ethanol. Avoid combination

Doxofylline: Sympathomimetics may enhance the adverse/toxic effect of Doxofylline. Monitor therapy

Doxylamine: May enhance the CNS depressant effect of CNS Depressants. Management: The manufacturer of Diclegis (doxylamine/pyridoxine), intended for use in pregnancy, specifically states that use with other CNS depressants is not recommended. Monitor therapy

Dronabinol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Droperidol: May enhance the CNS depressant effect of CNS Depressants. Management: Consider dose reductions of droperidol or of other CNS agents (eg, opioids, barbiturates) with concomitant use. Exceptions to this monograph are discussed in further detail in separate drug interaction monographs. Consider therapy modification

Eluxadoline: Anticholinergic Agents may enhance the constipating effect of Eluxadoline. Avoid combination

Ergot Derivatives: May enhance the hypertensive effect of Alpha1-Agonists. Ergot Derivatives may enhance the vasoconstricting effect of Alpha1-Agonists. Exceptions: Ergoloid Mesylates; Nicergoline. Avoid combination

Esketamine: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Flunitrazepam: CNS Depressants may enhance the CNS depressant effect of Flunitrazepam. Management: Reduce the dose of CNS depressants when combined with flunitrazepam and monitor patients for evidence of CNS depression (eg, sedation, respiratory depression). Use non-CNS depressant alternatives when available. Consider therapy modification

Fosphenytoin-Phenytoin: Chlorpheniramine may increase the serum concentration of Fosphenytoin-Phenytoin. Monitor therapy

Gastrointestinal Agents (Prokinetic): Anticholinergic Agents may diminish the therapeutic effect of Gastrointestinal Agents (Prokinetic). Monitor therapy

Glucagon: Anticholinergic Agents may enhance the adverse/toxic effect of Glucagon. Specifically, the risk of gastrointestinal adverse effects may be increased. Monitor therapy

Glycopyrrolate (Oral Inhalation): Anticholinergic Agents may enhance the anticholinergic effect of Glycopyrrolate (Oral Inhalation). Avoid combination

Glycopyrronium (Topical): May enhance the anticholinergic effect of Anticholinergic Agents. Avoid combination

Guanethidine: May enhance the arrhythmogenic effect of Sympathomimetics. Guanethidine may enhance the hypertensive effect of Sympathomimetics. Monitor therapy

Hyaluronidase: May enhance the vasoconstricting effect of Phenylephrine (Systemic). Management: Avoid the use of hyaluronidase to enhance dispersion or absorption of phenylephrine. Use of hyaluronidase for other purposes in patients receiving phenylephrine may be considered as clinically indicated. Avoid combination

HydrOXYzine: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Iobenguane Radiopharmaceutical Products: Alpha1-Agonists may diminish the therapeutic effect of Iobenguane Radiopharmaceutical Products. Management: Discontinue all drugs that may inhibit or interfere with catecholamine transport or uptake for at least 5 biological half-lives before iobenguane administration. Do not administer these drugs until at least 7 days after each iobenguane dose. Avoid combination

Ioflupane I 123: Phenylephrine (Systemic) may diminish the diagnostic effect of Ioflupane I 123. Monitor therapy

Ipratropium (Oral Inhalation): May enhance the anticholinergic effect of Anticholinergic Agents. Avoid combination

Itopride: Anticholinergic Agents may diminish the therapeutic effect of Itopride. Monitor therapy

Kava Kava: May enhance the adverse/toxic effect of CNS Depressants. Monitor therapy

Lemborexant: May enhance the CNS depressant effect of CNS Depressants. Management: Dosage adjustments of lemborexant and of concomitant CNS depressants may be necessary when administered together because of potentially additive CNS depressant effects. Close monitoring for CNS depressant effects is necessary. Consider therapy modification

Levosulpiride: Anticholinergic Agents may diminish the therapeutic effect of Levosulpiride. Avoid combination

Lofexidine: May enhance the CNS depressant effect of CNS Depressants. Management: Drugs listed as exceptions to this monograph are discussed in further detail in separate drug interaction monographs. Monitor therapy

Lumefantrine: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

Magnesium Sulfate: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Memantine: NMDA Receptor Antagonists may enhance the adverse/toxic effect of Memantine. Monitor therapy

Methotrimeprazine: Products Containing Ethanol may enhance the adverse/toxic effect of Methotrimeprazine. Specifically, CNS depressant effects may be increased. Management: Avoid products containing alcohol in patients treated with methotrimeprazine. Avoid combination

Metoclopramide: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

MetyroSINE: CNS Depressants may enhance the sedative effect of MetyroSINE. Monitor therapy

Mianserin: May enhance the anticholinergic effect of Anticholinergic Agents. Monitor therapy

Minocycline (Systemic): May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Mirabegron: Anticholinergic Agents may enhance the adverse/toxic effect of Mirabegron. Monitor therapy

Monoamine Oxidase Inhibitors: May enhance the serotonergic effect of Dextromethorphan. This may cause serotonin syndrome. Avoid combination

Nabilone: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Nitroglycerin: Anticholinergic Agents may decrease the absorption of Nitroglycerin. Specifically, anticholinergic agents may decrease the dissolution of sublingual nitroglycerin tablets, possibly impairing or slowing nitroglycerin absorption. Monitor therapy

Opioid Agonists: CNS Depressants may enhance the CNS depressant effect of Opioid Agonists. Management: Avoid concomitant use of opioid agonists and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Consider therapy modification

Orphenadrine: CNS Depressants may enhance the CNS depressant effect of Orphenadrine. Avoid combination

Oxatomide: May enhance the anticholinergic effect of Anticholinergic Agents. Avoid combination

Oxomemazine: May enhance the CNS depressant effect of CNS Depressants. Avoid combination

Oxybate Salt Products: CNS Depressants may enhance the CNS depressant effect of Oxybate Salt Products. Management: Consider alternatives to this combination when possible. If combined, dose reduction or discontinuation of one or more CNS depressants (including the oxybate salt product) should be considered. Interupt oxybate salt treatment during short-term opioid use. Consider therapy modification

OxyCODONE: CNS Depressants may enhance the CNS depressant effect of OxyCODONE. Management: Avoid concomitant use of oxycodone and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Consider therapy modification

Ozanimod: May enhance the hypertensive effect of Sympathomimetics. Management: Concomitant use of ozanimod with sympathomimetic agents is not recommended. If combined, monitor patients closely for the development of hypertension, including hypertensive crises. Consider therapy modification

Paraldehyde: CNS Depressants may enhance the CNS depressant effect of Paraldehyde. Avoid combination

Parecoxib: May increase the serum concentration of Dextromethorphan. Monitor therapy

Peginterferon Alfa-2b: May decrease the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Peginterferon Alfa-2b may increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

Perampanel: May enhance the CNS depressant effect of CNS Depressants. Management: Patients taking perampanel with any other drug that has CNS depressant activities should avoid complex and high-risk activities, particularly those such as driving that require alertness and coordination, until they have experience using the combination. Consider therapy modification

Piribedil: CNS Depressants may enhance the CNS depressant effect of Piribedil. Monitor therapy

Pitolisant: Antihistamines may diminish the therapeutic effect of Pitolisant. Avoid combination

Potassium Chloride: Anticholinergic Agents may enhance the ulcerogenic effect of Potassium Chloride. Management: Patients on drugs with substantial anticholinergic effects should avoid using any solid oral dosage form of potassium chloride. Avoid combination

Potassium Citrate: Anticholinergic Agents may enhance the ulcerogenic effect of Potassium Citrate. Avoid combination

Pramipexole: CNS Depressants may enhance the sedative effect of Pramipexole. Monitor therapy

Pramlintide: May enhance the anticholinergic effect of Anticholinergic Agents. These effects are specific to the GI tract. Avoid combination

Procarbazine: May enhance the adverse/toxic effect of Sympathomimetics. Management: Consider alternatives to this combination when possible. Procarbazine prescribing information states that this combination should be avoided. Consider therapy modification

Propacetamol: May increase the serum concentration of Phenylephrine (Systemic). Management: Monitor patients closely for increased side effects of phenylephrine if propacetamol is used concomitantly. Patients with underlying blood pressure issues or arrhythmias may need closer monitoring and may warrant consideration of alternative therapies. Monitor therapy

Ramosetron: Anticholinergic Agents may enhance the constipating effect of Ramosetron. Monitor therapy

Revefenacin: Anticholinergic Agents may enhance the anticholinergic effect of Revefenacin. Avoid combination

ROPINIRole: CNS Depressants may enhance the sedative effect of ROPINIRole. Monitor therapy

Rotigotine: CNS Depressants may enhance the sedative effect of Rotigotine. Monitor therapy

Rufinamide: May enhance the adverse/toxic effect of CNS Depressants. Specifically, sleepiness and dizziness may be enhanced. Monitor therapy

Secretin: Anticholinergic Agents may diminish the therapeutic effect of Secretin. Management: Avoid concomitant use of anticholinergic agents and secretin. Discontinue anticholinergic agents at least 5 half-lives prior to administration of secretin. Consider therapy modification

Selective Serotonin Reuptake Inhibitors (Strong CYP2D6 Inhibitors): Dextromethorphan may enhance the serotonergic effect of Selective Serotonin Reuptake Inhibitors (Strong CYP2D6 Inhibitors). This could result in serotonin syndrome. Selective Serotonin Reuptake Inhibitors (Strong CYP2D6 Inhibitors) may increase the serum concentration of Dextromethorphan. Management: Consider alternatives to this drug combination. If combined, monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes). Consider therapy modification

Serotonergic Agents (High Risk): Dextromethorphan may enhance the serotonergic effect of Serotonergic Agents (High Risk). This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) when these agents are combined. Exceptions: FLUoxetine; Isocarboxazid; Linezolid; Methylene Blue; Moclobemide; PARoxetine; Phenelzine; Tranylcypromine. Monitor therapy

Solriamfetol: Sympathomimetics may enhance the hypertensive effect of Solriamfetol. Sympathomimetics may enhance the tachycardic effect of Solriamfetol. Monitor therapy

Suvorexant: CNS Depressants may enhance the CNS depressant effect of Suvorexant. Management: Dose reduction of suvorexant and/or any other CNS depressant may be necessary. Use of suvorexant with alcohol is not recommended, and the use of suvorexant with any other drug to treat insomnia is not recommended. Consider therapy modification

Sympathomimetics: May enhance the adverse/toxic effect of other Sympathomimetics. Monitor therapy

Tedizolid: May enhance the hypertensive effect of Sympathomimetics. Tedizolid may enhance the tachycardic effect of Sympathomimetics. Monitor therapy

Tetrahydrocannabinol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Tetrahydrocannabinol and Cannabidiol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Thalidomide: CNS Depressants may enhance the CNS depressant effect of Thalidomide. Avoid combination

Thiazide and Thiazide-Like Diuretics: Anticholinergic Agents may increase the serum concentration of Thiazide and Thiazide-Like Diuretics. Monitor therapy

Thioridazine: Chlorpheniramine may enhance the arrhythmogenic effect of Thioridazine. Thioridazine may increase the serum concentration of Chlorpheniramine. Management: Avoid this combination when possible. If used, monitor closely for arrhythmia as well as general toxicity of chlorpheniramine. Consider therapy modification

Tiotropium: Anticholinergic Agents may enhance the anticholinergic effect of Tiotropium. Avoid combination

Topiramate: Anticholinergic Agents may enhance the adverse/toxic effect of Topiramate. Monitor therapy

Trimeprazine: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Umeclidinium: May enhance the anticholinergic effect of Anticholinergic Agents. Avoid combination

Zolpidem: CNS Depressants may enhance the CNS depressant effect of Zolpidem. Management: Reduce the Intermezzo brand sublingual zolpidem adult dose to 1.75 mg for men who are also receiving other CNS depressants. No such dose change is recommended for women. Avoid use with other CNS depressants at bedtime; avoid use with alcohol. Consider therapy modification

Test Interactions

See individual agents.

Adverse Reactions

See individual agents.

Warnings/Precautions

Concerns related to adverse effects:

• CNS depression: May cause CNS depression, which may impair physical or mental abilities; patients must be cautioned about performing tasks which require mental alertness (eg, operating machinery or driving).

Disease-related concerns:

• Asthma: Use with caution in patients with a history of asthma.

• Cardiovascular disease: Use with caution in patients with cardiovascular disease (including hypertension and ischemic heart disease); contraindicated with severe disease.

• Diabetes: Use with caution in patients with diabetes mellitus.

• Increased intraocular pressure: Use with caution in patients with increased intraocular pressure.

• Prostatic hyperplasia/urinary obstruction: Use with caution in patients with prostatic hyperplasia and/or GU obstruction.

• Pyloroduodenal obstruction: Use with caution in patients with pyloroduodenal obstruction (including stenotic peptic ulcer).

• Respiratory disease: Use with caution in patients with asthma or other chronic breathing disorders.

• Thyroid dysfunction: Use with caution in patients with thyroid dysfunction.

Concurrent drug therapy issues:

• Sedatives: Effects may be potentiated when used with other sedative drugs or ethanol.

Special populations:

• CYP2D6 poor metabolizers: Dextromethorphan is metabolized by hepatic CYP2D6. Poor metabolizers of CYP2D6 may have exaggerated or prolonged effects of dextromethorphan. Increased risk may be seen with concomitant use of potent CYP2D6 inhibitors; use with caution (Abduljalil 2010; Jurica 2012; Sager 2014; Zhou 2009).

• Elderly: Use with caution in the elderly; may be more sensitive to adverse effects.

• Pediatric: Antihistamines may cause excitation in young children.

Other warnings/precautions:

• Self-medication (OTC use): When used for self-medication (OTC), notify healthcare provider if symptoms do not improve within 7 days or are accompanied by fever, rash, or persistent headache. Discontinue and contact healthcare provider if nervousness, dizziness, or sleeplessness occur.

Pregnancy Considerations

Refer to individual monographs.

Patient Education

What is this drug used for?

• It is used to treat nose stuffiness.

• It is used to ease allergy signs.

• It is used to relieve coughing.

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

• Dizziness

• Anxiety

• Trouble sleeping

• Fatigue

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.

Note: This is not a comprehensive list of all side effects. Talk to your doctor if you have questions.

Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a limited summary of general information about the medicine's uses from the patient education leaflet and is not intended to be comprehensive. This limited summary does NOT include all information available about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not intended to provide medical advice, diagnosis or treatment and does not replace information you receive from the healthcare provider. For a more detailed summary of information about the risks and benefits of using this medicine, please speak with your healthcare provider and review the entire patient education leaflet.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.