Comparative Pharmacology
Head-to-head clinical analysis: PROMETHAZINE versus TRIPHED.
Peer-Reviewed Evidence
Head-to-head clinical analysis: PROMETHAZINE versus TRIPHED.
PROMETHAZINE vs TRIPHED
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.
Triprolidine is a first-generation antihistamine that competitively antagonizes histamine at H1 receptors, thereby alleviating symptoms of allergic reactions. Pseudoephedrine is a sympathomimetic amine that acts as a decongestant by stimulating alpha-adrenergic receptors in the respiratory tract mucosa, causing vasoconstriction and reducing edema.
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: Triprolidine 2.5 mg / pseudoephedrine 60 mg orally every 4-6 hours, not to exceed 4 doses in 24 hours.
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.
Terminal elimination half-life is 6-8 hours in adults with normal renal function; clinically, dosing interval adjustments are recommended in renal impairment.
Renal (70-80% as metabolites, <1% unchanged); biliary/fecal minor.
Renal excretion of unchanged drug and metabolites accounting for approximately 60-70% of elimination; biliary/fecal elimination accounts for 20-30%.
Category A/B
Category C
Antihistamine / Antiemetic
Antihistamine/Decongestant Combination
Promethazine + Clotrimazole
"The metabolism of Clotrimazole can be decreased when combined with Promethazine."