Comparative Pharmacology
Head-to-head clinical analysis: BENADRYL PRESERVATIVE FREE versus CETIRIZINE HYDROCHLORIDE HIVES RELIEF.
Peer-Reviewed Evidence
Head-to-head clinical analysis: BENADRYL PRESERVATIVE FREE versus CETIRIZINE HYDROCHLORIDE HIVES RELIEF.
BENADRYL PRESERVATIVE FREE vs CETIRIZINE HYDROCHLORIDE HIVES RELIEF
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 peripheral H1-receptor antagonist. Competitively inhibits histamine at the H1 receptor, preventing histamine-mediated symptoms such as pruritus, sneezing, and rhinorrhea.
25-50 mg IV/IM every 4-6 hours as needed; maximum single dose 100 mg, maximum daily dose 400 mg.
Oral, 10 mg once daily; may be increased to 10 mg twice daily if needed.
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 8-11 hours in healthy adults; increases to approximately 20 hours in renal impairment (CrCl <40 mL/min).
Primarily renal (90% as metabolites and unchanged drug); ~1% excreted in feces via bile. Unchanged diphenhydramine accounts for <5% of urinary recovery.
Approximately 70% of the dose is excreted unchanged in urine via glomerular filtration and tubular secretion; 10% is excreted in feces. Biliary excretion is minimal.
Category C
Category A/B
Antihistamine
Antihistamine