Comparative Pharmacology
Head-to-head clinical analysis: METOZOLV ODT versus PROMETHAZINE W DEXTROMETHORPHAN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: METOZOLV ODT versus PROMETHAZINE W DEXTROMETHORPHAN.
METOZOLV ODT vs PROMETHAZINE W/ DEXTROMETHORPHAN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Selective 5-HT3 receptor antagonist; blocks serotonin action at vagal nerve terminals and in the chemoreceptor trigger zone, inhibiting emetic reflex.
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.
2.5 mg to 5 mg orally once daily, as disintegrating tablet; may increase to 10 mg if needed
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
~1.5–2 hours in normal renal function; prolonged to 10–20 hours in severe renal impairment (CrCl <30 mL/min).
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: ~70% as unchanged drug; biliary/fecal: ~30% as metabolites and unchanged drug.
Renal: promethazine ~6% unchanged, dextromethorphan ~0.5% unchanged; metabolites primarily renal. Biliary/fecal: minor routes for both.
Category C
Category A/B
Antiemetic
Antihistamine / Antiemetic