Comparative Pharmacology
Head-to-head clinical analysis: PROMETHAZINE versus TIGAN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: PROMETHAZINE versus TIGAN.
PROMETHAZINE vs TIGAN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
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.
TIGAN (trimethobenzamide) acts on the chemoreceptor trigger zone (CTZ) to inhibit emetic stimuli, primarily through antagonism of dopamine D2 receptors, though its exact mechanism is not fully elucidated.
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.
Adults: 200 mg IM or 100 mg PO or 200 mg PR every 6–8 hours as needed.
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 9-16 hours; may be prolonged in hepatic impairment.
12-15 hours; may be prolonged in hepatic impairment.
Renal (70-80% as metabolites, <1% unchanged); biliary/fecal minor.
Renal (30-50% as unchanged drug and metabolites), biliary/fecal (minor).
Category A/B
Category C
Antihistamine / Antiemetic
Antiemetic
Promethazine + Clotrimazole
"The metabolism of Clotrimazole can be decreased when combined with Promethazine."