Comparative Pharmacology
Head-to-head clinical analysis: MEZOFY versus PROMETHAZINE W DEXTROMETHORPHAN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: MEZOFY versus PROMETHAZINE W DEXTROMETHORPHAN.
MEZOFY vs PROMETHAZINE W/ DEXTROMETHORPHAN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
MEZOFY is a selective serotonin reuptake inhibitor (SSRI) that potentiates serotonergic activity in the CNS by inhibiting the reuptake of serotonin at the presynaptic neuronal membrane.
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.
MEZOFY (mexiletine) 200 mg orally every 8 hours; may increase to 300 mg every 8 hours if needed.
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: 8-12 hours (mean 10 h); prolonged in renal impairment (up to 24 h in CrCl <30 mL/min)
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: 60% unchanged; biliary/fecal: 25% as metabolites; 15% other
Renal: promethazine ~6% unchanged, dextromethorphan ~0.5% unchanged; metabolites primarily renal. Biliary/fecal: minor routes for both.
Category C
Category A/B
Antiemetic/Antivertigo
Antihistamine / Antiemetic