Comparative Pharmacology
Head-to-head clinical analysis: EMEND versus PROMETHAZINE W CODEINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: EMEND versus PROMETHAZINE W CODEINE.
EMEND vs PROMETHAZINE W/ CODEINE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Selective substance P/neurokinin 1 (NK1) receptor antagonist, which inhibits the binding of substance P in the emetic pathway.
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.
125 mg orally once 1 hour before chemotherapy; then 80 mg orally once daily on Days 2 and 3.
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
9–13 hours (terminal) in healthy adults; clinically, this supports once-daily dosing. In patients with severe renal impairment (CrCl <30 mL/min), half-life is prolonged to ~16 hours.
Promethazine: 10-19 hours (terminal). Codeine: 2.5-3.5 hours (terminal); prolonged in renal impairment.
Primarily metabolized; ~5% unchanged in urine, ~57% in feces as metabolites, ~32% in urine as metabolites. Renal elimination of parent drug is minimal.
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