Comparative Pharmacology
Head-to-head clinical analysis: PROMETHAZINE DM versus TIGAN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: PROMETHAZINE DM versus TIGAN.
PROMETHAZINE DM vs TIGAN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Promethazine is a phenothiazine derivative that acts as a histamine H1 receptor antagonist, antiemetic via blockade of dopamine D2 receptors in the chemoreceptor trigger zone, and sedative via central anticholinergic effects. Dextromethorphan is an NMDA receptor antagonist and sigma-1 receptor agonist, suppressing cough by central action on the cough center.
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.
2 teaspoonfuls (10 mL) orally every 4-6 hours, not to exceed 8 teaspoonfuls (40 mL) per 24 hours.
Adults: 200 mg IM or 100 mg PO or 200 mg PR every 6–8 hours as needed.
None Documented
None Documented
16-19 hours (terminal); note: effect may last longer due to active metabolites and tissue binding
12-15 hours; may be prolonged in hepatic impairment.
Renal (70-80% as metabolites, <1% unchanged); biliary/fecal (20-30%)
Renal (30-50% as unchanged drug and metabolites), biliary/fecal (minor).
Category A/B
Category C
Antihistamine / Antiemetic
Antiemetic