Comparative Pharmacology
Head-to-head clinical analysis: DIPHENHYDRAMINE HYDROCHLORIDE versus HYDRAMINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DIPHENHYDRAMINE HYDROCHLORIDE versus HYDRAMINE.
DIPHENHYDRAMINE HYDROCHLORIDE vs HYDRAMINE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Competitive antagonist of histamine H1 receptors, reducing allergic symptoms; also exerts anticholinergic, sedative, and antiemetic effects via central and peripheral receptor blockade.
Antagonist of histamine H1 receptors, preventing histamine-mediated responses such as vasodilation, bronchoconstriction, and increased capillary permeability.
25-50 mg orally or intramuscularly every 4-6 hours as needed; maximum 300 mg per day.
50-100 mg IV/IM every 4-6 hours, maximum 400 mg per day. Also available as 50 mg oral tablets.
None Documented
None Documented
Terminal elimination half-life 4–10 hours (mean ~7 hours); prolonged in elderly, hepatic impairment, and with CYP2D6 poor metabolizers.
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)
Renal elimination of metabolites accounts for ~60% of the dose; <5% excreted unchanged. Fecal excretion ~40% via bile.
Primarily renal (95%) as metabolites; <5% unchanged; 5% fecal
Category A/B
Category C
Antihistamine
Antihistamine
Diphenhydramine + Sulfisoxazole
"The metabolism of Sulfisoxazole can be decreased when combined with Diphenhydramine."