Levocetirizine: a new selective H1 receptor antagonist for use in allergic disorders

Abstract

Levocetirizine is the active R-enantiomer of cetirizine and represents a new second-generation histamine H(1) antagonist. It has a high affinity and selectivity for H(1) receptors. Comparative studies have shown evidence of superior H(1) receptor binding affinity over its racemate, cetirizine. Levocetirizine has a favorable pharmacokinetic profile; it is rapidly and extensively absorbed, minimally metabolized, and has a lower volume of distribution (V(d)) than some other second-generation antihistamines. A number of studies using the histamine-induced wheal and flare model have repeatedly demonstrated marked suppressive effects for levocetirizine. Levocetirizine has also been found to be effective in relieving symptoms of seasonal and perennial allergic rhinitis, including nasal congestion, and its side effects are minor.