Comparative Pharmacology
Head-to-head clinical analysis: PERIACTIN versus PROMETHAZINE W DEXTROMETHORPHAN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: PERIACTIN versus PROMETHAZINE W DEXTROMETHORPHAN.
PERIACTIN vs PROMETHAZINE W/ DEXTROMETHORPHAN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Cyproheptadine is a first-generation antihistamine with anticholinergic and antiserotonergic properties. It acts as a competitive antagonist at histamine H1 receptors and serotonin 5-HT2 receptors, thereby inhibiting histamine-mediated allergic symptoms and serotonin-mediated effects such as increased gastrointestinal motility and vascular permeability.
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 three times daily; adjust as needed. Maximum: 32 mg/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
10-12 hours terminal elimination half-life; steady-state reached in 2-3 days
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 (40-50% as metabolites, <5% unchanged); biliary/fecal (minor, ~10-20%)
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