Comparative Pharmacology
Head-to-head clinical analysis: ANTIVERT versus PROMETHAZINE W DEXTROMETHORPHAN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ANTIVERT versus PROMETHAZINE W DEXTROMETHORPHAN.
ANTIVERT vs PROMETHAZINE W/ DEXTROMETHORPHAN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Antivert (meclizine) is a piperazine H1 histamine receptor antagonist with central anticholinergic and sedative properties. It suppresses the chemoreceptor trigger zone and labyrinthine apparatus, reducing vestibular stimulation and vertigo.
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.
25-100 mg orally daily in divided doses 2-4 times daily; maximum 400 mg/day.
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 elimination half-life is 35–50 hours in adults; prolonged in renal impairment.
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.
Primarily renal (urine) as unchanged drug and metabolites; biliary excretion is minimal. Approximately 80% excreted unchanged in urine.
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