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Dextromethorphan

Medically reviewed by Drugs.com. Last updated on Oct 2, 2020.

Pronunciation

(deks troe meth OR fan)

Dosage Forms

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

Capsule, Oral, as hydrobromide:

Robafen Cough: 15 mg [contains brilliant blue fcf (fd&c blue #1), fd&c red #40]

Robitussin Lingering CoughGels: 15 mg [contains brilliant blue fcf (fd&c blue #1), fd&c red #40, polyethylene glycol, propylene glycol]

Gel, Oral, as hydrobromide:

ElixSure Cough: 7.5 mg/5 mL (120 mL) [alcohol free; contains carbomer 934p, propylene glycol, propylparaben; cherry bubblegum flavor]

Liquid, Oral, as hydrobromide:

Buckleys Cough: 12.5 mg/5 mL (118 mL) [alcohol free, sugar free; contains butylparaben, menthol, propylparaben, saccharin sodium]

Little Colds Cough Formula: 7.5 mg/mL (30 mL) [alcohol free, dye free, saccharin free; contains sodium benzoate; grape flavor]

PediaCare Childrens Long-Act: 7.5 mg/5 mL (118 mL) [contains brilliant blue fcf (fd&c blue #1), saccharin sodium, sodium benzoate]

Robitussin Lingering LA Cough: 15 mg/5 mL (118 mL [DSC]) [contains alcohol, usp, fd&c red #40, menthol, saccharin sodium, sodium benzoate]

Scot-Tussin Diabetes CF: 10 mg/5 mL (480 mL [DSC], 3780 mL [DSC]) [alcohol free, dye free, fructose free, sodium free, sorbitol free, sugar free]

Triaminic Long Acting Cough: 7.5 mg/5 mL (118 mL) [alcohol free, dye free, pseudoephedrine free; contains benzoic acid, propylene glycol]

Lozenge, Mouth/Throat, as hydrobromide:

Hold: 5 mg (10 ea)

Hold: 5 mg (10 ea) [cherry flavor]

Strip, Oral, as hydrobromide:

Triaminic Long Acting Cough: 7.5 mg (14 ea, 16 ea) [contains alcohol, usp, fd&c red #40; cherry flavor]

Triaminic Long Acting Cough: 7.5 mg (14 ea) [contains alcohol, usp, fd&c red #40, isopropyl alcohol]

Suspension Extended Release, Oral:

Cough DM: Dextromethorphan polistirex [equivalent to dextromethorphan hydrobromide 30 mg/5 mL] (89 mL) [alcohol free; contains fd&c yellow #10 aluminum lake, methylparaben, polysorbate 80, propylparaben, sodium metabisulfite; orange flavor]

Delsym: Dextromethorphan polistirex [equivalent to dextromethorphan hydrobromide 30 mg/5 mL] (89 mL [DSC], 148 mL [DSC]) [alcohol free; contains brilliant blue fcf (fd&c blue #1), disodium edta, methylparaben, polyethylene glycol, polysorbate 80, propylene glycol, propylparaben]

Delsym: Dextromethorphan polistirex [equivalent to dextromethorphan hydrobromide 30 mg/5 mL] (89 mL, 148 mL) [alcohol free; contains brilliant blue fcf (fd&c blue #1), disodium edta, methylparaben, polyethylene glycol, polysorbate 80, propylene glycol, propylparaben; grape flavor]

Delsym: Dextromethorphan polistirex [equivalent to dextromethorphan hydrobromide 30 mg/5 mL] (89 mL [DSC], 148 mL [DSC]) [alcohol free; contains edetate disodium, fd&c yellow #6 (sunset yellow), methylparaben, polyethylene glycol, polysorbate 80, propylene glycol, propylparaben]

Delsym: Dextromethorphan polistirex [equivalent to dextromethorphan hydrobromide 30 mg/5 mL] (89 mL, 148 mL) [alcohol free; contains edetate disodium, fd&c yellow #6 (sunset yellow), methylparaben, polyethylene glycol, polysorbate 80, propylene glycol, propylparaben; orange flavor]

Delsym Cough Childrens: Dextromethorphan polistirex [equivalent to dextromethorphan hydrobromide 30 mg/5 mL] (89 mL, 148 mL) [alcohol free; contains brilliant blue fcf (fd&c blue #1), edetate disodium, methylparaben, polyethylene glycol, polysorbate 80, propylene glycol, propylparaben, soybean oil; grape flavor]

Delsym Cough Childrens: Dextromethorphan polistirex [equivalent to dextromethorphan hydrobromide 30 mg/5 mL] (89 mL, 148 mL) [alcohol free; contains edetate disodium, fd&c yellow #6 (sunset yellow), methylparaben, polyethylene glycol, polysorbate 80, propylene glycol, propylparaben, soybean oil; orange flavor]

GoodSense Cough DM: Dextromethorphan polistirex [equivalent to dextromethorphan hydrobromide 30 mg/5 mL] (148 mL) [alcohol free, gluten free; contains fd&c yellow #10 aluminum lake, methylparaben, polysorbate 80, propylparaben, sodium metabisulfite]

GoodSense Cough DM Childrens: Dextromethorphan polistirex [equivalent to dextromethorphan hydrobromide 30 mg/5 mL] (89 mL, 148 mL) [alcohol free, gluten free; contains fd&c yellow #10 aluminum lake, methylparaben, polysorbate 80, propylparaben, sodium metabisulfite]

Robitussin 12 Hour Cough: Dextromethorphan polistirex [equivalent to dextromethorphan hydrobromide 30 mg/5 mL] (89 mL) [alcohol free; contains brilliant blue fcf (fd&c blue #1), methylparaben, polysorbate 80, propylparaben, sodium metabisulfite]

Robitussin 12 Hour Cough: Dextromethorphan polistirex [equivalent to dextromethorphan hydrobromide 30 mg/5 mL] (89 mL) [alcohol free; contains fd&c yellow #10 (quinoline yellow), methylparaben, polysorbate 80, propylparaben, sodium metabisulfite]

Robitussin 12 Hour Cough Child: Dextromethorphan polistirex [equivalent to dextromethorphan hydrobromide 30 mg/5 mL] (89 mL) [alcohol free; contains brilliant blue fcf (fd&c blue #1), methylparaben, polysorbate 80, propylparaben, sodium metabisulfite]

Generic: Dextromethorphan polistirex [equivalent to dextromethorphan hydrobromide 30 mg/5 mL] (89 mL)

Syrup, Oral, as hydrobromide:

Creomulsion Adult: 20 mg/15 mL (118 mL [DSC])

Creomulsion for Children: 5 mg/5 mL (118 mL [DSC]) [cherry flavor]

Robitussin Childrens Cough LA: 7.5 mg/5 mL (118 mL) [alcohol free; contains fd&c red #40, propylene glycol, saccharin sodium, sodium benzoate; fruit punch flavor]

Silphen DM Cough: 10 mg/5 mL (118 mL) [contains alcohol, usp; strawberry flavor]

Triaminic Long Acting Cough: 7.5 mg/5 mL (118 mL [DSC]) [alcohol free, dye free; contains benzoic acid, edetate disodium, propylene glycol]

Brand Names: U.S.

  • Buckleys Cough [OTC]
  • Cough DM [OTC]
  • Creomulsion Adult [OTC] [DSC]
  • Creomulsion for Children [OTC] [DSC]
  • Delsym Cough Childrens [OTC]
  • Delsym [OTC]
  • ElixSure Cough [OTC]
  • GoodSense Cough DM Childrens [OTC]
  • GoodSense Cough DM [OTC]
  • Hold [OTC]
  • Little Colds Cough Formula [OTC]
  • PediaCare Childrens Long-Act [OTC]
  • Robafen Cough [OTC]
  • Robitussin 12 Hour Cough Child [OTC]
  • Robitussin 12 Hour Cough [OTC]
  • Robitussin Childrens Cough LA [OTC]
  • Robitussin Lingering CoughGels [OTC]
  • Robitussin Lingering LA Cough [OTC] [DSC]
  • Scot-Tussin Diabetes CF [OTC] [DSC]
  • Silphen DM Cough [OTC]
  • Triaminic Long Acting Cough [OTC]

Pharmacologic Category

  • Antitussive
  • N-Methyl-D-Aspartate (NMDA) Receptor Antagonist

Pharmacology

Decreases the sensitivity of cough receptors and interrupts cough impulse transmission by depressing the medullary cough center through sigma receptor stimulation; structurally related to codeine

Metabolism

Hepatic via demethylation via CYP2D6 to dextrorphan (active); CYP3A4 and CYP3A5 form smaller amounts of 3-hydroxy and 3-methoxy derivatives.

Excretion

Primarily in urine as metabolites.

Onset of Action

Antitussive: 15 to 30 minutes.

Time to Peak

Children 2 to 5 years: 1.44 ± 0.563 hours (Guenin 2014).

Children 6 to 11 years: 2.12 ± 0.801 hours (Guenin 2014).

Children ≥12 years and Adolescents: 2.04 ± 0.865 hours (Guenin 2014).

Adults: Mean range: 2.1 to 2.6 hours (Silvasti 1987).

Peak concentration:

Pediatric patients: Excluding poor metabolizers (Guenin 2014).

Children 2 to 5 years (following doses of 7.5 to 11.25 mg): 1.47 ± 1.597 ng/mL.

Children 6 to 11 years (following doses of 15 to 24.75 mg): 1.26 ± 1.211 ng/mL.

Children ≥12 years and Adolescents (following doses of 30 mg): 4.9 ± 4.215 ng/mL.

Adults (following doses of 60 mg): Mean range: 5.2 to 5.8 ng/mL (Silvasti 1987).

Half-Life Elimination

Dextromethorphan:

Pediatric patients: Excluding poor metabolizers (Guenin 2014).

Children 2 to 5 years: 4.09 ± 1.44 hours.

Children 6 to 11 years: 4.8 ± 1.59 hours.

Children ≥12 years and Adolescents: 6.41 ± 1.639 hours.

Adults: Extensive metabolizers: 2 to 4 hours; poor metabolizers: 24 hours.

Special Populations Note

Metabolism: Pharmacokinetic parameters are affected by the genetic predisposition of CYP2D6 activity (Guenin 2014).

Use: Labeled Indications

Cough (suppressant): Temporary control of cough due to minor throat and bronchial irritation associated with the common cold or inhaled irritants; temporary relief of cough impulse to improve sleep (extended release formulations)

Contraindications

Concurrent administration with or within 2 weeks of discontinuing an MAO inhibitor

Dosing: Adult

Cough suppressant: Oral: 10 to 20 mg every 4 hours or 20 to 30 mg every 6 to 8 hours; extended release: 60 mg twice daily; maximum: 120 mg/24 hours

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

Note: Safety and efficacy for the use of cough and cold products in infants and young children limited; the AAP warns against the use of these products for respiratory illnesses in infants and young children (AAP 2018; FDA 2017).

Cough suppressant: Oral:

Oral syrup (immediate release):

Children 2 to <6 years: 5 mg every 4 hours as needed; do not exceed 6 doses in 24 hours.

Children 6 to <12 years: 10 mg every 4 hours as needed; do not exceed 6 doses in 24 hours.

Children ≥12 years and Adolescents: 20 mg every 4 hours as needed; do not exceed 6 doses in 24 hours.

Long-acting liquid: Children ≥12 years and Adolescents: 30 mg every 6 to 8 hours as needed; do not exceed 4 doses in 24 hours.

Oral capsule: Children ≥12 years and Adolescents: 30 mg every 6 to 8 hours as needed; do not exceed 4 doses in 24 hours.

Extended-release suspension (dextromethorphan polistirex):

Children 4 to <6 years: 15 mg every 12 hours as needed; do not exceed 30 mg in 24 hours.

Children 6 to <12 years: 30 mg every 12 hours as needed; do not exceed 60 mg in 24 hours.

Children ≥12 years and Adolescents: 60 mg every 12 hours as needed; do not exceed 120 mg in 24 hours.

Administration

Shake extended release suspension well before use. Only use dosing cup provided to measure liquid doses.

Dietary Considerations

Some products may contain sodium.

Drug Interactions

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

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

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

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

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

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

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. Monitor therapy

Test Interactions

False-positive phencyclidine, opioids and heroin urine drug screen

Adverse Reactions

The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified.

Frequency not defined.

Central nervous system: Dizziness, drowsiness, nervousness, restlessness

Gastrointestinal: Gastrointestinal distress, nausea, stomach pain, vomiting

Warnings/Precautions

Concurrent drug therapy issues:

• Serotonin syndrome: Symptoms of agitation, confusion, hallucinations, hyper-reflexia, myoclonus, shivering, and tachycardia may occur with concomitant proserotonergic drugs (ie, SSRIs/SNRIs or triptans); especially with higher dextromethorphan doses.

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).

• Debilitated patients: Use with caution in patients who are sedated, debilitated or confined to a supine position.

• Pediatric: Use with caution in atopic children. Not for OTC use in children <4 years of age.

Dosage form specific issues:

• Benzyl alcohol and derivatives: Some dosage forms may contain sodium benzoate/benzoic acid; benzoic acid (benzoate) is a metabolite of benzyl alcohol; large amounts of benzyl alcohol (≥99 mg/kg/day) have been associated with a potentially fatal toxicity (“gasping syndrome”) in neonates; the “gasping syndrome” consists of metabolic acidosis, respiratory distress, gasping respirations, CNS dysfunction (including convulsions, intracranial hemorrhage), hypotension, and cardiovascular collapse (AAP ["Inactive" 1997]; CDC, 1982); some data suggests that benzoate displaces bilirubin from protein binding sites (Ahlfors, 2001); avoid or use dosage forms containing benzyl alcohol derivative with caution in neonates. See manufacturer’s labeling.

• Tartrazine: Some products may contain tartrazine.

Other warnings/precautions:

• Abuse/misuse: Healthcare providers should be alert to problems of abuse or misuse. Abuse can cause death, brain damage, seizure, loss of consciousness, and irregular heartbeat.

• 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. Do not use for persistent or chronic cough (as with smoking, asthma, chronic bronchitis, emphysema) or if cough is accompanied by excessive phlegm unless directed to do so by healthcare provider.

Pregnancy Considerations

Dextromethorphan is metabolized in the liver via CYP2D6 and CYP3A enzymes. The activity of both enzymes is increased in the mother during pregnancy (Tracy 2005; Wadelius 1997). In the fetus, CYP2D6 activity is low in the fetal liver and CYP3A4 activity is present by ~17 weeks' gestation (Jacqz-Aigrain 1992).

When an antitussive is needed during pregnancy, dextromethorphan at standard OTC doses is generally considered acceptable. Some sources recommend use be reserved for significant maternal need; products containing alcohol should be avoided (Chasnoff 1981; Conover 2003; Koren 1998; Ward 2005).

Patient Education

What is this drug used for?

• It is used to relieve coughing.

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.

Frequently Asked Questions