Comparative Pharmacology
Head-to-head clinical analysis: DIPHENHYDRAMINE versus DYMISTA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DIPHENHYDRAMINE versus DYMISTA.
Diphenhydramine vs DYMISTA
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.
Azelastine is a histamine H1-receptor antagonist; fluticasone propionate is a corticosteroid with anti-inflammatory activity. The combination reduces nasal symptoms by blocking histamine receptors and inhibiting inflammatory mediators.
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).
One spray (137 mcg azelastine hydrochloride/50 mcg fluticasone propionate) per nostril twice daily, intranasal.
None Documented
None Documented
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 4-8 hours in adults; prolonged in hepatic impairment (up to 20 hours) and elderly.
Azelastine: terminal half-life ~22 hours (plasma) with long-lasting antihistamine effect. Fluticasone propionate: terminal half-life ~7.8 hours (intravenous), but intranasal systemic exposure is very low.
Primarily renal (90-95% as metabolites, <5% unchanged). Minor biliary/fecal elimination (<5%).
Azelastine: ~75% renal (primarily as parent and metabolites), ~25% fecal. Fluticasone propionate: <5% renal, >95% fecal as parent and metabolites.
Category C
Category C
Antihistamine
Antihistamine/Corticosteroid Combination
Diphenhydramine + Sulfisoxazole
"The metabolism of Sulfisoxazole can be decreased when combined with Diphenhydramine."