Comparative Pharmacology
Head-to-head clinical analysis: CYPROHEPTADINE HYDROCHLORIDE versus PROMETHAZINE WITH CODEINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CYPROHEPTADINE HYDROCHLORIDE versus PROMETHAZINE WITH CODEINE.
CYPROHEPTADINE HYDROCHLORIDE vs PROMETHAZINE WITH 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.
Promethazine is a phenothiazine derivative that antagonizes histamine at H1 receptors, acting as a sedative and antiemetic. Codeine is an opioid agonist at mu-opioid receptors, producing analgesia and antitussive effects via central nervous system depression.
4 mg orally three times daily; range 4-20 mg/day, not to exceed 0.5 mg/kg/day
10-20 mg promethazine and 10-20 mg codeine (based on phosphate) orally every 4-6 hours as needed for cough; maximum daily codeine dose 120 mg.
None Documented
None Documented
Terminal half-life approximately 8–16 hours in adults; may be prolonged in elderly or hepatic impairment.
Promethazine: 9-16 hours (mean 12 hours), clinically significant for sedation duration. Codeine: 2.5-4 hours (mean 3 hours), with active metabolite morphine 2-3 hours.
Primarily renal (appreciable unchanged drug and metabolites); biliary/fecal elimination minor (<5%).
Promethazine: renal 70% as metabolites and unchanged drug, biliary/fecal 20-30%. Codeine: renal 90% (5-15% unchanged, rest as morphine and conjugates), fecal <10%.
Category A/B
Category A/B
Antihistamine
Antihistamine / Antiemetic