Comparative Pharmacology
Head-to-head clinical analysis: HYDRAMINE versus PROMETHAZINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: HYDRAMINE versus PROMETHAZINE.
HYDRAMINE vs PROMETHAZINE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Antagonist of histamine H1 receptors, preventing histamine-mediated responses such as vasodilation, bronchoconstriction, and increased capillary permeability.
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.
50-100 mg IV/IM every 4-6 hours, maximum 400 mg per day. Also available as 50 mg oral tablets.
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.
MODERATE Risk
MODERATE Risk
Clinical Note
moderateDiphenhydramine + Deferasirox
"The serum concentration of Deferasirox can be increased when it is combined with Diphenhydramine."
Clinical Note
moderateDiphenhydramine + Fluticasone propionate
"The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Fluticasone propionate."
Clinical Note
moderateDiphenhydramine + Tenofovir disoproxil
"The metabolism of Tenofovir disoproxil can be decreased when combined with Diphenhydramine."
Clinical Note
moderateTerminal elimination half-life 5.7 hours, range 4.2-7.7 hours; prolonged in hepatic impairment (up to 15 hours in cirrhosis)
Terminal elimination half-life 9-16 hours; may be prolonged in hepatic impairment.
Primarily renal (95%) as metabolites; <5% unchanged; 5% fecal
Renal (70-80% as metabolites, <1% unchanged); biliary/fecal minor.
Category C
Category A/B
Antihistamine
Antihistamine / Antiemetic
Promethazine + 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."