Comparative Pharmacology
Head-to-head clinical analysis: PROCHLORPERAZINE versus PROMETHAZINE HYDROCHLORIDE AND DEXTROMETHORPHAN HYDROBROMIDE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: PROCHLORPERAZINE versus PROMETHAZINE HYDROCHLORIDE AND DEXTROMETHORPHAN HYDROBROMIDE.
PROCHLORPERAZINE vs PROMETHAZINE HYDROCHLORIDE AND DEXTROMETHORPHAN HYDROBROMIDE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Prochlorperazine is a phenothiazine antipsychotic that acts as a dopamine D2 receptor antagonist in the chemoreceptor trigger zone (CTZ) and at high doses in the mesolimbic system. It also has anticholinergic and antiemetic effects.
Promethazine is a phenothiazine derivative that acts as a histamine H1 receptor antagonist, antiemetic, and sedative. Dextromethorphan is a cough suppressant that acts as an NMDA receptor antagonist and sigma-1 receptor agonist.
5-10 mg IM/IV every 3-4 hours as needed; or 5-10 mg PO 3-4 times daily; or 25 mg PR twice daily. Maximum IM/IV: 40 mg/day; PO: 40 mg/day.
For cough and upper respiratory symptoms: 5 mL (containing promethazine hydrochloride 6.25 mg and dextromethorphan hydrobromide 15 mg) orally every 4 to 6 hours, not to exceed 30 mL in 24 hours.
None Documented
None Documented
Clinical Note
moderateProchlorperazine + Fluticasone propionate
"The risk or severity of adverse effects can be increased when Prochlorperazine is combined with Fluticasone propionate."
Clinical Note
moderateProchlorperazine + Haloperidol
"The metabolism of Haloperidol can be decreased when combined with Prochlorperazine."
Clinical Note
moderateProchlorperazine + Methylphenidate
"The risk or severity of adverse effects can be increased when Prochlorperazine is combined with Methylphenidate."
Clinical Note
moderateTerminal elimination half-life: 23-25 hours, with prolonged elimination in hepatic impairment.
Promethazine: 10-19 hours (mean 12 hours). Dextromethorphan: extensive metabolizers (CYP2D6) 3-5 hours; poor metabolizers 20-30 hours. Clinical context: accumulation with repeated dosing, especially in poor metabolizers.
Renal: 70-80% (as metabolites), Fecal: 20-30% (unchanged and metabolites), Biliary: 10-15% of dose excreted in bile.
Promethazine: primarily hepatic metabolism, renal excretion of metabolites (~70%, <1% unchanged); fecal excretion (20-30%). Dextromethorphan: hepatic metabolism, renal excretion of metabolites and <1% unchanged drug.
Category A/B
Category A/B
Typical Antipsychotic / Antiemetic
Antihistamine / Antiemetic
Prochlorperazine + Quinagolide
"The therapeutic efficacy of Quinagolide can be decreased when used in combination with Prochlorperazine."