Comparative Pharmacology
Head-to-head clinical analysis: BENADRYL PRESERVATIVE FREE versus FEXOFENADINE HYDROCHLORIDE HIVES.
Peer-Reviewed Evidence
Head-to-head clinical analysis: BENADRYL PRESERVATIVE FREE versus FEXOFENADINE HYDROCHLORIDE HIVES.
BENADRYL PRESERVATIVE FREE vs FEXOFENADINE HYDROCHLORIDE HIVES
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.
Fexofenadine hydrochloride is a selective peripheral H1-receptor antagonist. It blocks the action of histamine at the H1 receptor, preventing histamine-mediated symptoms such as itching, sneezing, rhinorrhea, and urticaria.
25-50 mg IV/IM every 4-6 hours as needed; maximum single dose 100 mg, maximum daily dose 400 mg.
60 mg orally twice daily or 180 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).
Terminal elimination half-life is 14.4 hours (range 11–17 hours) in healthy adults. Clinically, this supports twice-daily dosing for symptomatic relief.
Primarily renal (90% as metabolites and unchanged drug); ~1% excreted in feces via bile. Unchanged diphenhydramine accounts for <5% of urinary recovery.
Approximately 95% of the dose is excreted unchanged in feces (80%) and urine (15%). Fexofenadine undergoes minimal hepatic metabolism (<5%).
Category C
Category A/B
Antihistamine
Antihistamine