Comparative Pharmacology
Head-to-head clinical analysis: PROMETHAZINE W CODEINE versus TIGAN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: PROMETHAZINE W CODEINE versus TIGAN.
PROMETHAZINE W/ CODEINE vs TIGAN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
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.
TIGAN (trimethobenzamide) acts on the chemoreceptor trigger zone (CTZ) to inhibit emetic stimuli, primarily through antagonism of dopamine D2 receptors, though its exact mechanism is not fully elucidated.
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.
Adults: 200 mg IM or 100 mg PO or 200 mg PR every 6–8 hours as needed.
None Documented
None Documented
Promethazine: 10-19 hours (terminal). Codeine: 2.5-3.5 hours (terminal); prolonged in renal impairment.
12-15 hours; may be prolonged in hepatic impairment.
Promethazine: renal (70% as metabolites, <1% unchanged), fecal (20-30%). Codeine: renal (90%, of which 5-10% unchanged, rest as metabolites), fecal (minor).
Renal (30-50% as unchanged drug and metabolites), biliary/fecal (minor).
Category A/B
Category C
Antihistamine / Antiemetic
Antiemetic