Comparative Pharmacology
Head-to-head clinical analysis: BROMPHENIRAMINE MALEATE versus PROMETHAZINE W DEXTROMETHORPHAN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: BROMPHENIRAMINE MALEATE versus PROMETHAZINE W DEXTROMETHORPHAN.
BROMPHENIRAMINE MALEATE vs PROMETHAZINE W/ DEXTROMETHORPHAN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Competitive antagonist of histamine at H1 receptor sites, suppressing histamine-induced vasodilation, increased capillary permeability, and bronchoconstriction.
Promethazine is a phenothiazine derivative that acts as a histamine H1 receptor antagonist and antiemetic; dextromethorphan is a non-opioid antitussive that acts as an NMDA receptor antagonist and sigma-1 receptor agonist.
4 mg orally every 4-6 hours, not to exceed 24 mg/day. Alternatively, extended-release: 12 mg every 12 hours.
5 mL (containing promethazine 6.25 mg and dextromethorphan 15 mg) orally every 4-6 hours as needed, not to exceed 30 mL (promethazine 37.5 mg, dextromethorphan 90 mg) per 24 hours.
None Documented
None Documented
Terminal half-life 22-25 hours; prolonged in hepatic impairment or elderly (up to 40 hours).
Promethazine: 9-16 h; dextromethorphan: 3-5 h (extensive metabolizers), 30-50 h (poor metabolizers). Clinical context: dosing interval typically 4-6 h for dextromethorphan; promethazine accumulates with repeated dosing.
Renal (85-90% as metabolites, 5-10% unchanged); biliary/fecal <5%.
Renal: promethazine ~6% unchanged, dextromethorphan ~0.5% unchanged; metabolites primarily renal. Biliary/fecal: minor routes for both.
Category C
Category A/B
Antihistamine
Antihistamine / Antiemetic