About Cetirizine Second Generation H1 Antagonist, Metabolite of hydroxyzine, Antihistamine. Mechanism of Action of Cetirizine This drug is a selective peripheral H1 receptor antagonist. Thus it inhibits the allergic symptoms produced by histamines like cold, rhinorrhea, sneezing, urticaria etc. The drug has some mast cell stabilizing properties. It also inhibit eotaxin-induced eosinophil TEM through both dermal and lung micro vascular endothelial cells. So inhibit eosinophil chemotaxis and also inflammation caused by it. Indications for Cetirizine 1. Sneezing 2. Rhinorrhoea 3. Postnasal discharge. 4. Common coughs 5. Colds. 6. Chronic urticaria 7. Dermatitis 8. Pruritic skin disorders 9. Hay fever 10. Angioedema