Comparative Pharmacology
Head-to-head clinical analysis: BENADRYL PRESERVATIVE FREE versus CHILDREN S ZYRTEC ALLERGY.
Peer-Reviewed Evidence
Head-to-head clinical analysis: BENADRYL PRESERVATIVE FREE versus CHILDREN S ZYRTEC ALLERGY.
BENADRYL PRESERVATIVE FREE vs CHILDREN'S ZYRTEC ALLERGY
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.
Cetirizine is a selective antagonist of peripheral H1 histamine receptors, inhibiting histamine-mediated allergic and inflammatory responses.
25-50 mg IV/IM every 4-6 hours as needed; maximum single dose 100 mg, maximum daily dose 400 mg.
5 mg (1 tablet or 5 mL oral solution) once daily; dosing frequency may be increased to 10 mg once daily (2 tablets or 10 mL) for more severe symptoms.
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 half-life 8.5–10.5 hours in children 2–5 years; 9–11 hours in children 6–12 years; 8–9 hours in adults. Clinically, supports once-daily dosing.
Primarily renal (90% as metabolites and unchanged drug); ~1% excreted in feces via bile. Unchanged diphenhydramine accounts for <5% of urinary recovery.
Primarily renal (60% unchanged) via tubular secretion; 40% metabolized in liver to inactive metabolites excreted in urine; <1% fecal.
Category C
Category C
Antihistamine
Antihistamine