Cetirizine Hydrochloride provided by us, is used to treat the symptoms of hay fever and other allergies. This drug is an antihistamine that helps with watery eyes, runny nose, itchy eyes/nose, sneezing, hives, and itching. It works by preventing your body from producing a natural molecule called histamine during an allergic reaction. Cetirizine Hydrochloride does not prevent or treat hives or a severe allergic response. If your doctor has recommended epinephrine to treat allergic reactions, keep your injector with you at all times.