Dextromethorphan (Monograph)

Brand names: Alka-Seltzer Plus Cold & Cough, Alka-Seltzer Plus Day Cold, Alka-Seltzer Plus Night Cold, Cheracol D Cough, Children’s Vicks NyQuil Cold/Cough, ... show all 52 brands
Drug class: Antitussives
ATC class: RO5DA09
VA class: RE302
CAS number: 6700-34-1

Medically reviewed by Drugs.com on Jan 22, 2024. Written by ASHP.

Introduction

Antitussive agent; derivative of levorphanol.

Uses for Dextromethorphan

Cough

Temporary relief of coughs (antitussive, cough suppressant) caused by minor throat and bronchial irritation that may occur with common colds, allergies, or inhaled irritants.

Used in fixed combination with other agents (e.g., acetaminophen, brompheniramine, chlorpheniramine, doxylamine, guaifenesin, phenylephrine, pseudoephedrine) for the temporary relief of coughs and/or other symptoms (e.g., rhinorrhea, sneezing, lacrimation, itching eyes, oronasopharyngeal itching, nasal congestion) associated with seasonal (e.g., hay fever) or perennial allergic rhinitis, other upper respiratory allergies, or the common cold.

Most effective in the treatment of chronic, nonproductive cough.

In pediatric patients <2 years of age, OTC cough and cold preparations (i.e., containing cough suppressants [including dextromethorphan], antihistamines, expectorants, and/or nasal decongestants) were not more effective than placebo in reducing acute cough and other symptoms of upper respiratory tract infection and reportedly are associated with adverse events and sometimes death (albeit rarely). (See Pediatric Use under Cautions.)

Abuse and recreational use reported. (See Abuse Potential under Cautions.)

Dextromethorphan Dosage and Administration

Administration

Oral Administration

Administer orally.

Dosage

Dosages of dextromethorphan hydrobromide and dextromethorphan polistirex are expressed in terms of dextromethorphan hydrobromide.

Because combinations and dosage strengths vary for fixed-combination preparations, consult manufacturer’s product labeling for appropriate dosage of the specific preparation.

Pediatric Patients

Cough

Immediate-release Preparations

Oral

Children <2 years of age: Dosage must be individualized. Currently there are no FDA-approved dosage recommendations for cough and cold preparations for children <2 years of age. (See Pediatric Use under Cautions.)

Children 2 to <6 years of age: 2.5–5 mg every 4 hours or 7.5 mg every 6–8 hours, not to exceed 30 mg daily, or as directed by a clinician. (See Pediatric Use under Cautions.)

Children 6 to <12 years of age: 5–10 mg every 4 hours or 15 mg every 6–8 hours, not to exceed 60 mg daily, or as directed by a clinician.

Children ≥12 years of age: 10–20 mg every 4 hours or 30 mg every 6–8 hours, not to exceed 120 mg daily, or as directed by a clinician.

Extended-release Oral Suspension (containing polistirex)

Oral

Children 2 to <6 years of age: 15 mg twice daily.

Children 6 to <12 years of age: 30 mg twice daily

Children ≥12 years of age: 60 mg twice daily.

Adults

Cough

Immediate-release Preparations

Oral

10–20 mg every 4 hours or 30 mg every 6–8 hours, not to exceed 120 mg daily, or as directed by a clinician.

Extended-release Oral Suspension (containing polistirex)

Oral

60 mg twice daily.

Prescribing Limits

Pediatric Patients

Cough

Oral

Children 2 to <6 years of age: Maximum 30 mg daily, or as directed by a clinician.

Children 6 to <12 years of age: Maximum 60 mg daily, or as directed by a clinician.

Children ≥12 years of age: Maximum 120 mg daily, or as directed by a clinician.

Adults

Cough

Oral

Maximum 120 mg daily, or as directed by a clinician.

Special Populations

Hepatic Impairment

No specific dosage recommendations for hepatic impairment.

Renal Impairment

No specific dosage recommendations for renal impairment.

Geriatric Patients

No specific geriatric dosage recommendations.

Cautions for Dextromethorphan

Contraindications

During or within 14 days of discontinuing MAO inhibitor therapy because of risk of serotonin syndrome. (See Interactions.)
Known hypersensitivity to the drug or any ingredient in the respective formulation.

Warnings/Precautions

Warnings

Persistent Cough

Do not take for persistent or chronic cough (e.g., with smoking, emphysema, asthma) or when coughing is accompanied by excessive secretions, unless directed by a clinician.

Consult a clinician for cough that persists for longer than 1 week, tends to recur, or is accompanied by fever, rash, or persistent headache.

Persistent cough may be a sign of a serious condition.

Sensitivity Reactions

May be associated with histamine release and should be used with caution in atopic children.

General Precautions

Sedated, Debilitated, and Supine Patients

Use with caution in sedated or debilitated patients and in patients confined to the supine position.

Phenylketonuria

Individuals with phenylketonuria and other individuals who must restrict their intake of phenylalanine should be warned that some commercially available preparations of dextromethorphan contain aspartame (NutraSweet), which is metabolized in the GI tract to phenylalanine.

Abuse Potential

Generally low, but recreational use reported with OTC dextromethorphan-containing preparations and with dextromethorphan powder sold illicitly.

Deaths possibly associated with ingestion of powdered dextromethorphan sold illicitly in capsules reported. Pure dextromethorphan in powder form reportedly is being encapsulated for illicit sale as a street drug.

Use of Fixed Combinations

When used in fixed combination with other agents (e.g., acetaminophen, brompheniramine, chlorpheniramine, doxylamine, guaifenesin, phenylephrine, pseudoephedrine), consider the cautions, precautions, and contraindications associated with the concomitant agent(s).

Specific Populations

Pregnancy

Category C.

Lactation

Unknown whether distributed into milk but likely based on low molecular weight. Preparations containing alcohol should be avoided in nursing women. Preparations that do not contain alcohol probably are safe.

Pediatric Use

Risk of overdosage and toxicity (including death) in children <2 years of age receiving OTC preparations containing antihistamines, cough suppressants, expectorants, and nasal decongestants alone or in combination for relief of symptoms of upper respiratory tract infection. Limited evidence of efficacy for these preparations in this age group; appropriate dosages not established. Therefore, FDA recommends not to use such preparations in children <2 years of age; safety and efficacy in older children under evaluation. Because children 2–3 years of age also are at increased risk of overdosage and toxicity, some manufacturers of oral nonprescription cough and cold preparations agreed to voluntarily revise the product labeling to state that such preparations should not be used in children <4 years of age. FDA recommends that parents and caregivers adhere to dosage instructions and warnings on the product labeling that accompanies the preparation and consult a clinician about any concerns. Clinicians should ask caregivers about use of OTC cough/cold preparations to avoid overdosage.

Efficacy of OTC cough and cold preparations in children <6 years of age also has been questioned. An FDA advisory panel recommended that these products not be used in these children; FDA has not yet announced its decision.

Do not use lozenges in children <6 years of age.

Do not use liquid-filled capsules in children <12 years of age, unless otherwise directed by a clinician.

Common Adverse Effects

Adverse effects with dextromethorphan are rare, but nausea and/or other GI disturbances, slight drowsiness, and dizziness sometimes occur.

Drug Interactions

Specific Drugs

Drug	Interaction	Comments
CNS depressants (e.g., alcohol, hypnotics, sedatives, tranquilizers, tricyclic antidepressants)	Possible additive CNS depression
MAO inhibitors	Concomitant therapy may produce serotonin syndrome, which can manifest with serious complications (e.g., hypertensive crisis, hyperpyrexia, cardiac arrhythmias, myoclonus), including death	Concomitant use with MAO inhibitors or within 2 weeks after discontinuance is contraindicated

Dextromethorphan Pharmacokinetics

Absorption

Bioavailability

Rapidly and well absorbed from the GI tract.

Onset

Exerts antitussive effect in 15–30 minutes after oral administration.

Duration

Approximately 3–6 hours with conventional dosage forms.

Elimination

Metabolism

Undergoes hepatic metabolism.

Elimination Route

Excreted primarily in urine.

Stability

Storage

Oral

Tight, light-resistant containers.

Compatibility

Dextromethorphan is incompatible with penicillins, tetracyclines, salicylates, phenobarbital sodium, hydriodic acid, and high concentrations of sodium or potassium iodide.

Actions

Retains only the antitussive activity of other morphinan derivatives.
Acts centrally on the respiratory center in the medulla and nucleus tractus solaris to increase the cough threshold.
About equal to codeine in depressing the cough reflex and has no expectorant action.

Advice to Patients

Risk of drowsiness; avoid alcohol and use caution when driving, operating machinery, or engaging in other hazardous tasks.
Importance of warning individuals with phenylketonuria and other individuals who must restrict their intake of phenylalanine that some commercially available preparations of dextromethorphan contain aspartame (NutraSweet), which is metabolized in the GI tract to phenylalanine following oral administration.
Importance of contacting a clinician if cough persists for longer than 1 week, tends to recur, or is accompanied by fever, rash, or persistent headache.
Advise patient not to use for persistent or chronic cough (e.g., with smoking, emphysema, asthma) or when coughing is accompanied by excessive secretions, unless directed by a clinician.
Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs (e.g., other cough and cold preparations) as well as any concomitant illnesses.

Importance of not using during or within 14 days of discontinuing MAO inhibitor therapy because of the risk of serotonin syndrome, which is potentially fatal. Advise patients to consult their pharmacist or clinician if they do not know whether drugs they are taking contain an MAO inhibitor.
Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed.
Importance of informing patients of other important precautionary information. (See Cautions.)

Preparations

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name

Dextromethorphan Hydrobromide
Routes	Dosage Forms	Strengths	Brand Names	Manufacturer
Oral	Capsules, liquid-filled	15 mg	Robitussin Long-Acting CoughGels	Pfizer
	Lozenges	5 mg	Hold DM	Ascher
		10 mg	Sucrets DM Cough Formula	Insight
	Solution	7.5 mg/5 mL*	Dextromethorphan Hydrobromide Solution
		10 mg/5 mL*	Dextromethorphan Hydrobromide Solution
			Vicks 44 Custom Care Dry Cough	Procter & Gamble
		15 mg/5 mL*	Dextromethorphan Hydrobromide Solution

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name

Dextromethorphan Hydrobromide Combinations
Routes	Dosage Forms	Strengths	Brand Names	Manufacturer
Oral	Capsules, liquid-filled	10 mg with Acetaminophen 325 mg, Chlorpheniramine Maleate 2 mg, and Phenylephrine Hydrochloride 5 mg	Alka-Seltzer Plus Cold & Cough Formula Liquid Gels	Bayer
			Tylenol Cold Multi-Symptom Nighttime Rapid Release Gels	McNeil
		10 mg with Acetaminophen 325 mg, Doxylamine Succinate 6.25 mg, and Phenylephrine Hydrochloride 5 mg	Alka-Seltzer Plus Night Cold Formula Liquid Gels	Bayer
		10 mg with Acetaminophen 325 mg and Phenylephrine Hydrochloride 5 mg	Alka-Seltzer Plus Day Cold Formula Liquid Gels	Bayer
			Vicks DayQuil Cold & Flu Relief LiquiCaps	Procter & Gamble
		15 mg with Acetaminophen 325 mg and Doxylamine Succinate 6.25 mg	Vicks NyQuil Cold & Flu Relief LiquiCaps	Procter & Gamble
	For solution	30 mg with Acetaminophen 1 g, Guaifenesin 400 mg, and Pseudoephedrine Hydrochloride 60 mg per packet	TheraFlu Max-D Severe Cold & Flu	Novartis
	Kit	12 Tablets, film-coated, Acetaminophen 325 mg with Dextromethorphan Hydrobromide 10 mg and Phenylephrine Hydrochloride 5 mg (Comtrex Daytime Caplets) 12 Tablets, film-coated, Acetaminophen 325 mg with Chlorpheniramine Maleate 2 mg, Dextromethorphan Hydrobromide 10 mg, and Phenylephrine Hydrochloride 5 mg (Comtrex Nighttime Caplets)	Comtrex Cold & Cough Day-Night Maximum Strength Caplets	Novartis
	Solution	3.3 mg/5 mL with Acetaminophen 108.3 mg/5 mL, Doxylamine Succinate 1.25 mg/5 mL, and Phenylephrine Hydrochloride 1.6 mg/5 mL	Tylenol Cold Multi-Symptom Nighttime	McNeil
		3.3 mg/5 mL with Acetaminophen 108.3 mg/5 mL, Guaifenesin 66.6 mg/5 mL, and Phenylephrine Hydrochloride 1.6 mg/5 mL	Tylenol Cold Multi-Symptom Severe	McNeil
			Tylenol Cold & Flu Severe	McNeil
		3.3 mg/5 mL with Acetaminophen 108.3 mg/5 mL and Phenylephrine Hydrochloride 1.6 mg/5 mL	Tylenol Cold Multi-Symptom Daytime	McNeil
			Vicks DayQuil Cold & Flu Relief	Procter & Gamble
		5 mg/5 mL with Acetaminophen 108.3 mg/5 mL and Doxylamine Succinate 2.08 mg/5 mL	Vicks NyQuil Cold & Flu Relief	Procter & Gamble
		5 mg/5 mL with Acetaminophen 160 mg/5 mL	Children’s Tylenol Plus Cough & Sore Throat	Prestige Brands
			TriaminicCough and Sore Throat	Novartis
		5 mg/5 mL with Acetaminophen 160 mg/5 mL and Chlorpheniramine Maleate 1 mg/5 mL	Children’s Tylenol Plus Cough & Runny Nose	McNeil
		5 mg/5 mL with Acetaminophen 160 mg/5 mL, Chlorpheniramine Maleate 1 mg/5 mL, and Phenylephrine Hydrochloride 2.5 mg/5 mL	Children’s Dimetapp Multi-Symptom Cold & Flu	Pfizer
			Children’s Tylenol Plus Flu	McNeil
		5 mg/5 mL with Acetaminophen 166.6 mg/5 mL	Tylenol Cold & Cough Daytime	McNeil
		5 mg/5 mL with Acetaminophen 166.6 mg/5 mL and Doxylamine Succinate 2.08 mg/5 mL	Tylenol Cold & Cough Nighttime	McNeil
		5 mg/5 mL with Brompheniramine Maleate 1 mg/5 mL and Phenylephrine Hydrochloride 2.5 mg/5 mL	Children’s Dimetapp Cold & Cough	Pfizer
		5 mg/5 mL with Chlorpheniramine Maleate 0.67 mg/5 mL	Children’s Vicks NyQuil Cold/Cough	Procter & Gamble
		5 mg/5 mL with Chlorpheniramine Maleate 1 mg/5 mL and Pseudoephedrine Hydrochloride 15 mg/5 mL	Kidkare Cough & Cold Liquid	Watson
		5 mg/5 mL with Doxylamine Succinate 2.08 mg/5 mL	Vicks NyQuil Cough	Procter & Gamble
		5 mg/5 mL with Guaifenesin 50 mg/5 mL and Phenylephrine Hydrochloride 2.5 mg/5 mL	Robitussin Children’s Cough & Cold CF	Pfizer
		5 mg/5 mL with Guaifenesin 100 mg/5 mL	Pediacare Cough & Congestion	Prestige Brands
		5 mg/5 mL with Phenylephrine Hydrochloride 2.5 mg/5 mL	Children’s Sudafed PE Cold & Cough	McNeil
			Pediacare Multi-Symptom Cold	Prestige Brands
			Triaminic Daytime Cold & Cough	Novartis
		6.7 mg/5 mL with Guaifenesin 66.7 mg/5 mL	Vicks Formula 44 Custom Care Chesty Cough	Procter & Gamble
		7.5 mg/5 mL with Acetaminophen 160 mg/5 mL and Chlorpheniramine Maleate 1 mg/5 mL	Triaminic Multi-Symptom Fever	Novartis
		10 mg/5 mL with Acetaminophen 216.7 mg/5 mL and Chlorpheniramine Maleate 1.3 mg/5 mL	Vicks Formula 44 Custom Care Cough & Cold PM	Procter & Gamble
		10 mg/5 mL with Guaifenesin 100 mg/5 mL*	Cheracol D Cough Formula	Lee
			Dextromethorphan Hydrobromide with Guaifenesin Syrup
			Diabetic Tussin DM	Health Care Products
			Guiatuss DM	Goldline
			Robitussin Peak Cold Cough + Chest Congestion DM	Pfizer
			Robitussin Sugar-Free Cough + Chest Congestion DM	Pfizer
		10 mg/5 mL with Guaifenesin 100 mg/5 mL and Phenylephrine Hydrochloride 5 mg/5 mL*	Robitussin Peak Cold Multi-Symptom Cold	Pfizer
		10 mg/5 mL with Guaifenesin 200 mg/5 mL	Diabetic Tussin DM Maximum Strength	Health Care Products
			Robitussin Maximum Strength Cough + Chest Congestion	Pfizer
			Robitussin Peak Cold Maximum Strength Cough + Chest Congestion	Pfizer
		15 mg/5 mL with Guaifenesin 100 mg/5 mL*	Safe Tussin	Kramer
		15 mg/5 mL with Promethazine Hydrochloride 6.25 mg/5 mL*	Promethazine Hydrochloride with Dextromethorphan Hydrobromide Cough Syrup
		5 mg/mL with Guaifenesin 50 mg/mL and Phenylephrine Hydrochloride 2.5 mg/mL	Suppress DX Pediatric Drops	Kramer Novis
	Suspension	5 mg/5 mL with Acetaminophen 160 mg/5 mL	Pediacare Fever Reducer Plus Cough & Sore Throat	Prestige Brands
		5 mg/5 mL with Acetaminophen 160 mg/5 mL and Chlorpheniramine Maleate 1 mg/5 mL	Pediacare Fever Reducer Plus Cough & Runny Nose	Prestige Brands
		5 mg/5 mL with Acetaminophen 160 mg/5 mL, Chlorpheniramine Maleate 1 mg/5 mL, and Phenylephrine Hydrochloride 2.5 mg/5 mL	Children’s Tylenol Plus Multi-Symptom Cold	McNeil
			Pediacare Fever Reducer Plus Multi-Symptom Cold	Prestige Brands
			Pediacare Fever Reducer Plus Flu	Prestige Brands
		5 mg/5 mL with Acetaminophen 160 mg/5 mL and Phenylephrine Hydrochloride 2.5 mg/5 mL	Pediacare Fever Reducer Plus Cold & Cough	Prestige Brands
	Tablets	10 mg with Acetaminophen 325 mg, Guaifenesin 200 mg, and Phenylephrine Hydrochloride 5 mg	Tylenol Cold & Flu Severe	McNeil
			Tylenol Cold Head Congestion Severe	McNeil
		10 mg with Acetaminophen 325 mg and Phenylephrine Hydrochloride 5 mg	Tylenol Cold Multi-Symptom Daytime	McNeil
		10 mg with Acetaminophen 325 mg and Phenylephrine Hydrochloride 15 mg	Comtrex Cold & Cough Multi-Symptom Relief Maximum Strength Tablets	Novartis
		30 mg with Chlorpheniramine Maleate 4 mg	Coricidin HBP Cough & Cold	Schering-Plough
	Tablets, chewable	10 mg with Chlorpheniramine Maleate 2 mg and Pseudoephedrine Hydrochloride 30 mg	Dicel DM	Centrix
	Tablets, extended-release	15 mg with Acetaminophen 500 mg and Chlorpheniramine Maleate 2 mg	Coricidin HBP Flu Maximum Strength	Schering-Plough
		30 mg with Guaifenesin 600 mg	Mucinex DM	Reckitt Benckiser
		60 mg with Guaifenesin 1200 mg	Maximum Strength Mucinex DM	Reckitt Benckiser
	Tablets, film-coated	10 mg with Acetaminophen 325 mg, Chlorpheniramine Maleate 2 mg, and Phenylephrine Hydrochloride 5 mg	TheraFlu Warming Relief Caplets Nighttime Multi-Symptom Cold	Novartis
		10 mg with Acetaminophen 325 mg and Phenylephrine Hydrochloride 5 mg	Comtrex Non-Drowsy Maximum Strength Caplets	Novartis
			TheraFlu Warming Relief Caplets Daytime Multi-Symptom Cold	Novartis
			Tylenol Cold Multi-Symptom Daytime	McNeil
		15 mg with Acetaminophen 325 mg, Guaifenesin 200 mg, and Phenylephrine Hydrochloride 5 mg	Tylenol Cold Head Congestion Severe	McNeil