Comparative Pharmacology
Head-to-head clinical analysis: BENADRYL PRESERVATIVE FREE versus XYZAL.
Peer-Reviewed Evidence
Head-to-head clinical analysis: BENADRYL PRESERVATIVE FREE versus XYZAL.
BENADRYL PRESERVATIVE FREE vs XYZAL
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.
Levocetirizine is a selective histamine H1-receptor antagonist; it inhibits the histamine-mediated responses in allergic conditions.
25-50 mg IV/IM every 4-6 hours as needed; maximum single dose 100 mg, maximum daily dose 400 mg.
5 mg orally once daily in the evening.
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 approximately 7 hours in healthy adults; prolonged to 8–11 hours in elderly and in renal impairment.
Primarily renal (90% as metabolites and unchanged drug); ~1% excreted in feces via bile. Unchanged diphenhydramine accounts for <5% of urinary recovery.
Approximately 84% of a dose is excreted renally as unchanged drug; 12% in feces via biliary elimination.
Category C
Category C
Antihistamine
Antihistamine