Comparative Pharmacology
Head-to-head clinical analysis: COMPAZINE versus PROMETHAZINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: COMPAZINE versus PROMETHAZINE.
COMPAZINE vs PROMETHAZINE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Dopamine D2 receptor antagonist in the chemoreceptor trigger zone; also blocks alpha-1 adrenergic, histamine H1, and muscarinic M1 receptors.
Promethazine is a phenothiazine derivative that acts as a potent histamine H1 receptor antagonist, thereby blocking the effects of histamine. It also has central anticholinergic, antiemetic, and sedative properties, likely mediated through antagonism at muscarinic, dopamine D2, and serotonin receptors in the brain.
5-10 mg IM/IV every 3-4 hours as needed; or 25 mg PO/PR twice daily for severe nausea/vomiting.
12.5-25 mg IM or IV every 4-6 hours; also 25 mg PO or PR every 6-8 hours. Maximum 100 mg/day.
None Documented
None Documented
Clinical Note
moderatePromethazine + Risedronic acid
"Promethazine can cause an increase in the absorption of Risedronic acid resulting in an increased serum concentration and potentially a worsening of adverse effects."
Clinical Note
moderatePromethazine + Methylphenidate
"Promethazine can cause an increase in the absorption of Methylphenidate resulting in an increased serum concentration and potentially a worsening of adverse effects."
Clinical Note
moderatePromethazine + Artesunate
"The serum concentration of Artesunate can be increased when it is combined with Promethazine."
Clinical Note
moderateTerminal elimination half-life is approximately 23 hours (range 15-30 hours) after oral or intramuscular administration. Clinical context: requires multiple daily dosing for steady state.
Terminal elimination half-life 9-16 hours; may be prolonged in hepatic impairment.
Renal (approximately 70% as metabolites, <1% unchanged), biliary/fecal (approximately 30%).
Renal (70-80% as metabolites, <1% unchanged); biliary/fecal minor.
Category C
Category A/B
Antipsychotic (Phenothiazine) / Antiemetic
Antihistamine / Antiemetic
Promethazine + Clotrimazole
"The metabolism of Clotrimazole can be decreased when combined with Promethazine."