dextromethorphan hydrobromide
Balminil D.M. ◆, Benylin DM, Benylin Pediatric, Broncho-Grippol-DM ◆, Children’s Hold, Creo-Terpin, Delsym, DM Syrup ◆, Diabetes CF, Drixoral Cough Liquid Caps, Hold DM, Koffex ◆, Neo-DM ◆, Pertussin CS, Pertussin ES, Robidex ◆, Robitussin Cough Calmers, Robitussin Pediatric, Scot-Tussin DM Cough Chasers, Sedatuss ◆, Silphen DM, St. Joseph Cough Suppressant for Children, Sucrets Cough Control Formula, Sucrets 4-Hour Cough, Suppress, Trocal, Vicks Dry Hacking Cough, Vicks Formula 44

Available forms
Available without a prescription
Capsules (liquid-filled): 30 mg
Liquid (sustained-release): 30 mg/5 ml
Lozenges: 5 mg, 7.5 mg, 15 mg
Solution: 3.5 mg/5 ml, 5 mg/5 ml, 7.5 mg/5 ml, 10 mg/5 ml, 12.5 mg/5 ml, 15 mg/5 ml
Syrup: 10 mg/5 ml, 15 mg/15 ml
Tablets: 200 mg

Indications and dosages
 Nonproductive cough (chronic). Adults and children age 12 and older: 10 to 20 mg P.O. q 4 hours. Or, 30 mg q 6 to 8 hours. Or, controlled-release liquid b.i.d. (60 mg b.i.d.). Maximum dose is 120 mg daily.
Children ages 6 to 12: 5 to 10 mg P.O. q 4 hours. Or, 15 mg q 6 to 8 hours. Or, controlled-release liquid b.i.d. (30 mg b.i.d.). Maximum dose is 60 mg daily.
Children ages 2 to 6: 2.5 to 5 mg P.O. q 4 hours. Or, 7.5 mg q 6 to 8 hours. Or, sustained-action liquid 15 mg b.i.d. Maximum dose is 30 mg daily.

Pharmacodynamics
Antitussive action: Dextromethorphan suppresses the cough reflex by direct action on the cough center in the medulla. Dextromethorphan is almost equal in antitussive potency to codeine but causes no analgesia or addiction and little or no CNS depression and has no expectorant action; it also produces fewer subjective and GI adverse effects than codeine. Treatment is intended to relieve cough frequency without abolishing protective cough reflex. In therapeutic doses, drug doesn’t inhibit ciliary activity.

Pharmacokinetics
Absorption: Absorbed readily from the GI tract.
Distribution: Unknown.
Metabolism: Metabolized extensively by the liver. Plasma half-life is about 11 hours.
Excretion: Little is excreted unchanged. Metabolites are excreted primarily in urine; about 7% to 10% is excreted in feces.

Contraindications and precautions
Contraindicated in patients currently taking MAO inhibitors or within 2 weeks of stopping an MAO inhibitor. Use cautiously in atopic children, sedated or debilitated patients, and patients confined to the supine position. Also use cautiously in patients sensitive to aspirin.

Interactions
Drug-drug. MAO inhibitors: May cause nausea, hypotension, excitation, hyperpyrexia, and coma. Don’t give dextromethorphan within 2 weeks after stopping an MAO inhibitor.
Selegiline: May cause confusion, coma, or hyperpyrexia. Avoid use together.
Drug-herb. Parsley: May promote or produce serotonin syndrome. Tell patient to avoid use together.

Adverse reactions
CNS: drowsiness, dizziness.
GI: nausea, vomiting, stomach pain.

Effects on lab test results
None reported.

Overdose and treatment
Signs and symptoms of overdose may include nausea, vomiting, drowsiness, dizziness, blurred vision, nystagmus, shallow respirations, urine retention, toxic psychosis, stupor, and coma.
 Treatment of overdose involves administering activated charcoal to reduce drug absorption and I.V. naloxone to support respiration. Other symptoms are treated supportively.

Special considerations
• Treatment is intended to relieve cough intensity and frequency without abolishing the protective cough reflex.
• May be used with percussion and chest vibration.
Breast-feeding patients
• Safety hasn’t been established.
Pediatric patients
• Don’t use syrup, tablets, or lozenges in children younger than age 2. Sustained-action liquid may be used in children younger than age 2, but dosage must be individualized.

Patient education
• Tell patient to report persistent cough lasting longer than 7 days.
• Instruct patient to use sugarless throat lozenges for throat irritation and resulting cough.
• Recommend a humidifier to filter out dust, smoke, and air pollutants.

Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE THREATENING.
◆ Canada only
◇ Unlabeled clinical use