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RESPIRATORY SYSTEM › COUGH AND COLD PREPARATIONS › COUGH SUPPRESSANTS, EXCL. COMBINATIONS WITH EXPECTORANTS › Opium alkaloids and derivatives
dextromethorphan
R05DA09
Forms & Strengths
- Oral Solution: 10 mg/5 mL, 15 mg/5 mL, 30 mg/5 mL
- Oral Syrup: 5 mg/5 mL, 15 mg/15 mL
- Extended-Release Oral Suspension: 30 mg/5 mL
- Chewable Tablets: 15 mg
- Lozenges/Troches: 5 mg, 7.5 mg, 15 mg
Adult Dosing
- Standard oral: 10 to 20 mg every 4 hours, or 30 mg every 6 to 8 hours as needed
- Extended-release suspension: 60 mg twice daily
- Maximum daily dose: 120 mg/day
Pediatric Dosing
- Children 2 to under 6 years: 2.5 to 5 mg every 4 hours (Max: 30 mg/day)
- Children 6 to under 12 years: 5 to 10 mg every 4 hours, or 15 mg every 6 to 8 hours (Max: 60 mg/day)
- Adolescents 12 years and older: Same as adult dosing (10-20 mg every 4h or 30 mg every 6-8h; Max: 120 mg/day)
Indications
- Symptomatic relief of cough caused by minor throat and bronchial irritation (e.g., common cold)
Mechanism of Action
- Acts centrally on the cough center in the medulla to elevate the threshold for coughing
- NMDA receptor antagonist and sigma-1 receptor agonist at higher doses
Contraindications
- Hypersensitivity to dextromethorphan
- Concurrent use of monoamine oxidase inhibitors (MAOIs) or within 14 days of cessation due to risk of serotonin syndrome
Adverse Reactions
- Dizziness
- Drowsiness
- Nausea and gastrointestinal upset
- Nervousness or restlessness (high doses)
- Serotonin syndrome (in overdose or with serotonergic drugs)
Drug Interactions
- MAOIs: Severe, potentially fatal serotonin syndrome
- SSRIs and other serotonergic agents: Increased risk of serotonin syndrome
- CYP2D6 inhibitors (e.g., fluoxetine, paroxetine, quinidine): Increased plasma concentrations and toxicity of dextromethorphan
- CNS depressants (alcohol, sedatives): Enhanced sedative effects
Curated Content: Needs Vetting Before Put to Clinical Use