Mechanism of Action

Levocetirizine, the active enantiomer of cetirizine, is an antihistamine; its principal effects are mediated via selective inhibition of H1 receptors. The antihistaminic activity of levocetirizine has been documented in a variety of animal and human models. In vitro binding studies revealed that levocetirizine has an affinity for the human H1-receptor 2-fold higher than that of cetirizine (Ki = 3 nmol/L vs. 6 nmol/L, respectively). The clinical relevance of this finding is unknown.

Indication

XYZAL is a histamine H1-receptor antagonist indicated for:

• The relief of symptoms associated with perennial allergic rhinitis
• The treatment of the uncomplicated skin manifestations of chronic idiopathic urticaria