Levocetirizine: The latest treatment option for allergic rhinitis and chronic idiopathic urticaria.

Levocetirizine is the most recent antihistamine available in the United States and is indicated for the symptomatic treatment of allergic rhinitis (AR; seasonal [SAR] and perennial [PAR]) and chronic idiopathic urticaria (CIU). The purpose of this study was to review the current literature on pharmacologic properties of levocetirizine, its safety, tolerability, and effectiveness in AR and CIU. Relevant articles in English or with English abstracts were identified from systematic Medline searches using combinations of the terms antihistamine/s, CIU, H(1)-receptor antagonist/s, levocetirizine, PAR and persistent AR (PER), pharmacodynamic, pharmacokinetic, and SAR. Levocetirizine is the active enantiomer of cetirizine. Pharmacologic and clinical studies indicate that levocetirizine has a fast onset and long duration of action, with a well-tolerated adverse effect profile. These favorable features may be caused by levocetirizine's pharmacokinetic and pharmacodynamic properties including high bioavailability, low apparent volume of distribution, low degree of metabolism, and high in vivo potency and H(1)-receptor occupancy. Several large well-controlled clinical trials in adults and children aged 6-12 years have shown levocetirizine to be consistently efficacious and well tolerated in relieving the symptoms of SAR, PAR, and PER and CIU. Levocetirizine is a welcome new treatment option in the United States for symptomatic treatment of AR and CIU.