Comparative Pharmacology
Head-to-head clinical analysis: KETOTIFEN FUMARATE versus PROMETHAZINE W DEXTROMETHORPHAN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: KETOTIFEN FUMARATE versus PROMETHAZINE W DEXTROMETHORPHAN.
KETOTIFEN FUMARATE vs PROMETHAZINE W/ DEXTROMETHORPHAN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Antihistamine and mast cell stabilizer; inhibits release of histamine and other mediators from mast cells; also blocks histamine H1 receptors.
Promethazine is a phenothiazine derivative that acts as a histamine H1 receptor antagonist and antiemetic; dextromethorphan is a non-opioid antitussive that acts as an NMDA receptor antagonist and sigma-1 receptor agonist.
1 mg orally twice daily; ophthalmic: 1 drop in each eye every 8-12 hours.
5 mL (containing promethazine 6.25 mg and dextromethorphan 15 mg) orally every 4-6 hours as needed, not to exceed 30 mL (promethazine 37.5 mg, dextromethorphan 90 mg) per 24 hours.
None Documented
None Documented
Terminal half-life 12-24 hours (mean 18 hours); requires twice-daily dosing after initial titration.
Promethazine: 9-16 h; dextromethorphan: 3-5 h (extensive metabolizers), 30-50 h (poor metabolizers). Clinical context: dosing interval typically 4-6 h for dextromethorphan; promethazine accumulates with repeated dosing.
Renal (50-70% as conjugates, <2% unchanged), fecal (<10%), with enterohepatic circulation.
Renal: promethazine ~6% unchanged, dextromethorphan ~0.5% unchanged; metabolites primarily renal. Biliary/fecal: minor routes for both.
Category A/B
Category A/B
Antihistamine / Mast Cell Stabilizer
Antihistamine / Antiemetic