The New Antihistamines-Desloratadine and Levocetirizine: A Review
December 2002 | Volume 1 | Issue 3 | Original Article | 311 | Copyright © December 2002
Noah Scheinfeld, MD
First generation antihistamines such as hydroxizine are effetive but cause sedation. The initial second generation antihistamines, terfanadine and astemizole, were effective non-sedating medications but had drug interactions that caused cardiac problem and have been pulled from the market in the United States. Later second generation antihistamines, such as loratidine and cetirizine, have been found to be effective in the treatment of allergic rhinitis, and the latter to be effective in the treatment of chronic idiopathic urticaria. More recently, third generation antihistamines have been developed from existing agents (e.g. desloratadine is the active metabolite of loratidine, levocetirizine is the racemically active component of cetirizine, and fexofenadine is a derivative of terfanadine) to increase effectiveness and decrease side effects. Desloratadine has been released in the United States and Europe, while levocetirizine is currently only available in Europe. This article will review over 50 clinical studies and reviews regarding desloratadine and levocetirizine with an overview of their possible dermatological use.