Cetirizine dihydrochloride

Cetirizine is a selective histamine H1 receptor antagonist with a Ki of 6 nM. It is a highly efficacious, well-tolerated, treatment for the management of Allergic Rhinitis. Cetirizine exerts anti-inflammatory effects apart from H1 antagonism. It significantly decreases the amounts of leukotriene B4 generated from neutrophil granulocytes. It inhibits aerosol histamine-induced bronchospasm in guinea pigs (ED₅₀ value of 100 μg/kg, p.o.).