Comparative Pharmacology
Head-to-head clinical analysis: DIPHENHYDRAMINE versus KETOTIFEN FUMARATE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DIPHENHYDRAMINE versus KETOTIFEN FUMARATE.
Diphenhydramine vs KETOTIFEN FUMARATE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Inverse agonist at histamine H1 receptors, blocking histamine-mediated effects in blood vessels, respiratory smooth muscle, and GI tract; also anticholinergic by blocking muscarinic receptors and sedative via central H1 receptor antagonism.
Antihistamine and mast cell stabilizer; inhibits release of histamine and other mediators from mast cells; also blocks histamine H1 receptors.
25-50 mg orally or intramuscularly every 4-6 hours; maximum 300 mg/day. Intravenous administration: 10-50 mg slow IV push (max 25 mg/min).
1 mg orally twice daily; ophthalmic: 1 drop in each eye every 8-12 hours.
None Documented
None Documented
Terminal elimination half-life 4-8 hours in adults; prolonged in hepatic impairment (up to 20 hours) and elderly.
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 half-life 12-24 hours (mean 18 hours); requires twice-daily dosing after initial titration.
Primarily renal (90-95% as metabolites, <5% unchanged). Minor biliary/fecal elimination (<5%).
Renal (50-70% as conjugates, <2% unchanged), fecal (<10%), with enterohepatic circulation.
Category C
Category A/B
Antihistamine
Antihistamine / Mast Cell Stabilizer
Diphenhydramine + Sulfisoxazole
"The metabolism of Sulfisoxazole can be decreased when combined with Diphenhydramine."