Comparative Pharmacology
Head-to-head clinical analysis: PROMETH PLAIN versus PROMETHAZINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: PROMETH PLAIN versus PROMETHAZINE.
PROMETH PLAIN vs PROMETHAZINE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Antagonist at histamine H1 receptors; also exhibits anticholinergic, antiemetic, and sedative effects.
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.
12.5-25 mg intramuscularly or intravenously every 4-6 hours as needed; maximum 100 mg/day.
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
Terminal elimination half-life is 10-14 hours in adults; may be prolonged in elderly or hepatic impairment.
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 9-16 hours; may be prolonged in hepatic impairment.
Primarily renal (approximately 70%) as metabolites and unchanged drug; biliary/fecal excretion accounts for ~20%.
Renal (70-80% as metabolites, <1% unchanged); biliary/fecal minor.
Category C
Category A/B
Antihistamine
Antihistamine / Antiemetic
Promethazine + Clotrimazole
"The metabolism of Clotrimazole can be decreased when combined with Promethazine."