Comparative Pharmacology
Head-to-head clinical analysis: PROMETHACON versus PROMETHAZINE W CODEINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: PROMETHACON versus PROMETHAZINE W CODEINE.
PROMETHACON vs PROMETHAZINE W/ CODEINE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Promethazine is a phenothiazine derivative with antihistaminic (H1 receptor antagonist), antiemetic, sedative, and anticholinergic properties. It inhibits central and peripheral H1 receptors, blocks dopamine D2 receptors in the chemoreceptor trigger zone, and has weak alpha-adrenergic blockade.
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.
25-50 mg intramuscularly or intravenously every 4-6 hours as needed. Maximum intravenous rate: 25 mg/minute. Maximum daily dose: 150 mg.
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: 4-6 hours in healthy adults; prolonged to 10-14 hours in hepatic impairment
Promethazine: 10-19 hours (terminal). Codeine: 2.5-3.5 hours (terminal); prolonged in renal impairment.
Renal (80%) as inactive metabolites, 20% fecal via bile
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
Antihistamine
Antihistamine / Antiemetic