Comparative Pharmacology
Head-to-head clinical analysis: CYPROHEPTADINE HYDROCHLORIDE versus PROMETHAZINE W CODEINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CYPROHEPTADINE HYDROCHLORIDE versus PROMETHAZINE W CODEINE.
CYPROHEPTADINE HYDROCHLORIDE vs PROMETHAZINE W/ CODEINE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Cyproheptadine is a potent antihistamine (H1 receptor antagonist) and antiserotonergic agent (5-HT2 receptor antagonist). It also exhibits weak anticholinergic and sedative properties. It blocks histamine-mediated vasodilation, increased capillary permeability, and pruritus, as well as serotonin-mediated effects on appetite and mood.
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.
4 mg orally three times daily; range 4-20 mg/day, not to exceed 0.5 mg/kg/day
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 half-life approximately 8–16 hours in adults; may be prolonged in elderly or hepatic impairment.
Promethazine: 10-19 hours (terminal). Codeine: 2.5-3.5 hours (terminal); prolonged in renal impairment.
Primarily renal (appreciable unchanged drug and metabolites); biliary/fecal elimination minor (<5%).
Promethazine: renal (70% as metabolites, <1% unchanged), fecal (20-30%). Codeine: renal (90%, of which 5-10% unchanged, rest as metabolites), fecal (minor).
Category A/B
Category A/B
Antihistamine
Antihistamine / Antiemetic