Comparative Pharmacology
Head-to-head clinical analysis: MAREZINE versus PROMETHAZINE W CODEINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: MAREZINE versus PROMETHAZINE W CODEINE.
MAREZINE vs PROMETHAZINE W/ CODEINE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Marezine (cyclizine) is a piperazine-derivative histamine H1-receptor antagonist with central anticholinergic and antiemetic activity. It competitively blocks H1 receptors in the vestibular apparatus and the chemoreceptor trigger zone (CTZ), suppressing nausea and vomiting. It also has antimuscarinic effects on the vomiting center.
Codeine is a prodrug converted to morphine, a mu-opioid receptor agonist, which inhibits nociceptive transmission; promethazine is a phenothiazine derivative with H1-receptor antagonism, anticholinergic, and antiemetic effects.
50 mg intramuscularly or intravenously every 4 to 6 hours as needed for motion sickness; 50 mg orally 30 to 60 minutes before travel, then every 4 to 6 hours up to 150 mg/24h.
10 mL (1 mg codeine, 6.25 mg promethazine per 5 mL) orally every 4-6 hours as needed for cough. Maximum: 60 mL per day. Do not exceed 5 days.
None Documented
None Documented
Terminal elimination half-life is 4-6 hours in adults; prolonged to 8-12 hours in elderly or hepatic impairment
Promethazine: 10-19 hours (terminal). Codeine: 2.5-3.5 hours (terminal); prolonged in renal impairment.
Renal: 70-80% as unchanged drug and metabolites; fecal: ~20%; biliary: minor
Promethazine: renal (70% as metabolites, <1% unchanged), fecal (20-30%). Codeine: renal (90%, of which 5-10% unchanged, rest as metabolites), fecal (minor).
Category C
Category A/B
Antiemetic
Antihistamine / Antiemetic