Brand/Trade Names: Virlix, Zirtek, Zyrtec
Description: 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.
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.
Like many other antihistamine medications, cetirizine is commonly prescribed in combination with pseudoephedrine hydrochloride, a decongestant. These combinations are marketed using the same brand name as the cetirizine with a “-D” suffix (Zyrtec-D, Virlix-D, etc.)
Uses: A potent second-generation histamine H1 antagonist that is effective in the treatment of symptoms associated with seasonal allergic rhinitis, perennial allergic rhinitis, the treatment of the uncomplicated skin manifestations of chronic idiopathic urticaria, and pollen-induced asthma. Unlike many traditional antihistamines, it does not cause drowsiness or anticholinergic side effects.