Comparative Pharmacology
Head-to-head clinical analysis: BENADRYL PRESERVATIVE FREE versus DISOMER.
Peer-Reviewed Evidence
Head-to-head clinical analysis: BENADRYL PRESERVATIVE FREE versus DISOMER.
BENADRYL PRESERVATIVE FREE vs DISOMER
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Diphenhydramine competitively antagonizes histamine at H1-receptors on effector cells, leading to relief of allergic symptoms. It also possesses anticholinergic, antiemetic, sedative, and local anesthetic effects.
Selective dopamine D2 receptor antagonist; also blocks alpha-1 adrenergic, histamine H1, and muscarinic M1 receptors.
25-50 mg IV/IM every 4-6 hours as needed; maximum single dose 100 mg, maximum daily dose 400 mg.
Adults: 1 mg orally once daily.
None Documented
None Documented
Terminal elimination half-life: 4-8 hours (mean ~5 hours). Prolonged in hepatic impairment (up to 2-fold) and elderly (7-12 hours).
12–15 hours in adults with normal renal function; prolonged to 30–40 hours in severe renal impairment (CrCl <30 mL/min).
Primarily renal (90% as metabolites and unchanged drug); ~1% excreted in feces via bile. Unchanged diphenhydramine accounts for <5% of urinary recovery.
Renal: 80% as unchanged drug; biliary/fecal: 15% as metabolites; <5% unchanged in feces.
Category C
Category C
Antihistamine
Antihistamine