Comparative Pharmacology
Head-to-head clinical analysis: PROCHLORPERAZINE versus PROMETHAZINE HYDROCHLORIDE AND CODEINE PHOSPHATE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: PROCHLORPERAZINE versus PROMETHAZINE HYDROCHLORIDE AND CODEINE PHOSPHATE.
PROCHLORPERAZINE vs PROMETHAZINE HYDROCHLORIDE AND CODEINE PHOSPHATE
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 antagonizes histamine H1 receptors, reducing allergic symptoms; it also has anticholinergic, antiemetic, and sedative effects. Codeine is an opioid agonist at mu-opioid receptors, producing analgesia and antitussive effects by central mechanisms.
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.
Adults: 5 mL (containing promethazine 6.25 mg and codeine 10 mg) orally every 4-6 hours as needed; maximum 30 mL per day.
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 (range 5-30h); Codeine: 2.5-4 hours (rapidly metabolized); Clinical context: sustained antitussive effect from codeine despite short half-life. Half-life of promethazine extends with hepatic impairment.
Renal: 70-80% (as metabolites), Fecal: 20-30% (unchanged and metabolites), Biliary: 10-15% of dose excreted in bile.
Renal: Codeine and metabolites ~90% (free and conjugated), Promethazine and metabolites primarily renal; minor biliary/fecal (<5% for codeine, ~6% for promethazine).
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."