Comparative Pharmacology
Head-to-head clinical analysis: PBZ SR versus PROMETHAZINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: PBZ SR versus PROMETHAZINE.
PBZ-SR vs PROMETHAZINE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Antihistamine; H1-receptor antagonist that competes with histamine for binding at H1 receptor sites, thereby preventing histamine-mediated allergic responses.
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.
100-200 mg orally every 12 hours; maximum 400 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
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 4-6 hours in adults with normal renal function; clinically relevant dosing every 4-6 hours is recommended.
Terminal elimination half-life 9-16 hours; may be prolonged in hepatic impairment.
Primarily renal excretion (80-90% as unchanged drug) via glomerular filtration and tubular secretion. Biliary/fecal excretion accounts for approximately 5-10%.
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."