Comparative Pharmacology
Head-to-head clinical analysis: BENADRYL PRESERVATIVE FREE versus DIPHENHYDRAMINE HYDROCHLORIDE PRESERVATIVE FREE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: BENADRYL PRESERVATIVE FREE versus DIPHENHYDRAMINE HYDROCHLORIDE PRESERVATIVE FREE.
BENADRYL PRESERVATIVE FREE vs DIPHENHYDRAMINE HYDROCHLORIDE PRESERVATIVE FREE
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.
Competitive antagonist of histamine H1 receptors; centrally acting anticholinergic agent that inhibits acetylcholine muscarinic receptors.
25-50 mg IV/IM every 4-6 hours as needed; maximum single dose 100 mg, maximum daily dose 400 mg.
25 to 50 mg intravenously or intramuscularly every 4 to 6 hours as needed; maximum 400 mg per day.
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).
Terminal elimination half-life: 4-10 hours (mean ~8 hours); prolonged in hepatic impairment or elderly (up to 20 hours).
Primarily renal (90% as metabolites and unchanged drug); ~1% excreted in feces via bile. Unchanged diphenhydramine accounts for <5% of urinary recovery.
Primarily renal as inactive metabolites; ~60% of a dose appears in urine as metabolites, with <5% unchanged. Minor biliary/fecal elimination (<10%).
Category C
Category A/B
Antihistamine
Antihistamine