Levocetirizine is the enantiomer of cetirizine, which falls into the group of competitive histamine antagonists and blocks up histamine receptors. The affinity for histamine receptors in levocetirizine is 2 times higher than that of cetirizine.
Levocetirizine affects the histamine-dependent stage of allergic reactions, and also reduces the migration of eosinophils, reduces vascular permeability, and limits the release of inflammatory mediators.
Levocetirizine prevents the development and facilitates the course of allergic reactions, has an antiexudative, antipruritic effect, practically has no anticholinergic and antiserotonin effect. In therapeutic doses, it practically does not have a sedative effect.