Brands, Medical Use, Clinical Data
- Anti-allergic Agents
Brands / Synonyms
Alerlisin; Cetirizina [Spanish]; Cetirizinum [Latin]; Cetrizine Hcl; Cetryn; Formistin; Hitrizin Film Tablet; Reactine; Setir; Virlix; Ziptek; Zirtek; Zyrlex; Zyrtec; Zyrtec
For the relief of symptoms associated with seasonal allergic rhinitis, perennial allergic rhinitis and the treatment of the uncomplicated skin manifestations of chronic idiopathic urticaria
Cetirizine, the active metabolite of the piperazine H1-receptor antagonist hydroxyzine, is used to treat chronic idiopathic urticaria, perennial allergic rhinitis, seasonal allergic rhinitis, allergic asthma, physical urticaria, and atopic dermatitis.
Mechanism of Action
Cetirizine competes with histamine for binding at H1-receptor sites on the effector cell surface, resulting in suppression of histaminic edema, flare, and pruritus. The low incidence of sedation can be attributed to reduced penetration of cetirizine into the CNS as a result of the less lipophilic carboxyl group on the ethylamine side chain.
mean peak plasma concentration (Cmax) of 114 ng/mL at a time (Tmax) of 2.2 hours postdose was observed for cetirizine
Somnolence (sleepiness or unusual drowsiness), restlessness, irritability
Biotrnasformation / Drug Metabolism
Cetirizine is contraindicated in those patients with a known hypersensitivity to it or any of its ingredients or
Pharmacokinetic interaction studies with cetirizine in adults were conducted with pseudoephedrine, antipyrine,
ketoconazole, erythromycin and azithromycin. No interactions were observed. In a multiple dose study of theophylline
(400 mg once daily for 3 days) and cetirizine (20 mg once daily for 3 days), a 16% decrease in the clearance of
cetirizine was observed. The disposition of theophylline was not altered by concomitant cetirizine
Drug-Drug Interactions: No clinically significant drug interactions have been found with
theophylline at a low dose, azithromycin, pseudoephedrine, ketoconazole, or erythromycin. There was a small decrease
in the clearance of cetirizine caused by a 400-mg dose of theophylline; it is possible that larger theophylline doses
could have a greater effect.