Zirtek allergy relief tablets keeps you free of any uncomfortable allergy symptoms all day long these are one a day tablets which contain the active ingredient cetirizine hydrochloride it works as an antihistamine against allergic reactions no drowsy side effects zirtek allergy relief tablets are 2nd generation antihistamines and do not cause drowsiness protects the whole family hayfever dust allergies pet dander allergies skin allergies and hives