Comparative Pharmacology
Head-to-head clinical analysis: CHLORPHENIRAMINE MALEATE versus PROMETHAZINE W DEXTROMETHORPHAN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CHLORPHENIRAMINE MALEATE versus PROMETHAZINE W DEXTROMETHORPHAN.
CHLORPHENIRAMINE MALEATE vs PROMETHAZINE W/ DEXTROMETHORPHAN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
H1 receptor antagonist; competitively blocks histamine at H1 receptors, preventing histamine-mediated symptoms such as vasodilation, increased capillary permeability, and smooth muscle contraction.
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.
4 mg orally every 4-6 hours, not to exceed 24 mg per day; or 10-20 mg intramuscularly or intravenously as a single dose, not to exceed 40 mg per day.
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
Clinical Note
moderateDexchlorpheniramine maleate + Haloperidol
"The metabolism of Haloperidol can be decreased when combined with Dexchlorpheniramine maleate."
Clinical Note
moderateDexchlorpheniramine maleate + Sulfisoxazole
"The metabolism of Sulfisoxazole can be decreased when combined with Dexchlorpheniramine maleate."
Clinical Note
moderateDexchlorpheniramine maleate + Erythromycin
"The metabolism of Erythromycin can be decreased when combined with Dexchlorpheniramine maleate."
Clinical Note
moderateTerminal elimination half-life: 12-15 hours (prolonged in hepatic impairment).
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% as metabolites; Fecal: negligible; Biliary: minor.
Renal: promethazine ~6% unchanged, dextromethorphan ~0.5% unchanged; metabolites primarily renal. Biliary/fecal: minor routes for both.
Category C
Category A/B
Antihistamine
Antihistamine / Antiemetic
Dexchlorpheniramine maleate + Cyclosporine
"The metabolism of Cyclosporine can be decreased when combined with Dexchlorpheniramine maleate."