Comparative Pharmacology
Head-to-head clinical analysis: BENADRYL versus CETIRIZINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: BENADRYL versus CETIRIZINE.
BENADRYL vs Cetirizine
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Antihistamine; inverse agonist at histamine H1 receptors, blocking histamine-induced vasodilation, increased capillary permeability, and bronchoconstriction; also anticholinergic and sedative.
Cetirizine is a selective second-generation H1-receptor antagonist that inhibits histamine release from mast cells and basophils, thereby reducing allergic symptoms.
25-50 mg orally every 4-6 hours as needed; maximum 300 mg per day. Alternatively, 10-50 mg intramuscularly or intravenously once, maximum 100 mg per dose (IV route preferred).
10 mg orally once daily; 5 mg orally once daily for mild symptoms
None Documented
None Documented
Terminal elimination half-life 4-8 hours; prolonged in hepatic impairment (up to 20 hours).
Clinical Note
moderateCetirizine + Fluticasone propionate
"The risk or severity of adverse effects can be increased when Cetirizine is combined with Fluticasone propionate."
Clinical Note
moderateLevocetirizine + Sulfisoxazole
"The metabolism of Sulfisoxazole can be decreased when combined with Levocetirizine."
Clinical Note
moderateLevocetirizine + Erythromycin
"The metabolism of Erythromycin can be decreased when combined with Levocetirizine."
Clinical Note
moderateLevocetirizine + Cyclosporine
Terminal elimination half-life is approximately 8.3 hours in healthy adults; extended to 20 hours in elderly and patients with renal impairment
Renal (90% as metabolites, <5% unchanged); minimal biliary/fecal.
Primarily renal (60% unchanged in urine); minor biliary/fecal (10%)
Category C
Category A/B
Antihistamine
Antihistamine
"The metabolism of Cyclosporine can be decreased when combined with Levocetirizine."