Comparative Pharmacology
Head-to-head clinical analysis: PROMETHAZINE W CODEINE versus TEMARIL.
Peer-Reviewed Evidence
Head-to-head clinical analysis: PROMETHAZINE W CODEINE versus TEMARIL.
PROMETHAZINE W/ CODEINE vs TEMARIL
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.
Temaril (trimeprazine tartrate and prednisolone) combines an antipruritic phenothiazine antihistamine with a corticosteroid. Trimeprazine blocks histamine H1 receptors, reducing pruritus and allergic reactions. Prednisolone suppresses inflammation via glucocorticoid receptor activation, inhibiting phospholipase A2 and cytokine production.
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.
2.5 mg orally twice daily or 5 mg orally at bedtime; maximum 10 mg/day.
None Documented
None Documented
Promethazine: 10-19 hours (terminal). Codeine: 2.5-3.5 hours (terminal); prolonged in renal impairment.
Terminal elimination half-life is 9–12 hours in adults; prolonged in hepatic impairment (up to 20 hours). Given TID dosing, steady state is reached within 2 days.
Promethazine: renal (70% as metabolites, <1% unchanged), fecal (20-30%). Codeine: renal (90%, of which 5-10% unchanged, rest as metabolites), fecal (minor).
Primarily via kidneys as metabolites; unchanged drug accounts for <1%. Biliary/fecal excretion is minor. Approx. 90% recovered in urine within 24 hours.
Category A/B
Category C
Antihistamine / Antiemetic
Antihistamine