Xyzal (Levocetirizine) is an antihistamine that reduces the effects of natural chemical histamine in the body. Histamine can produce symptoms of sneezing, itching, watery eyes, and runny nose. Xyzal is used to treat symptoms of year-round (perennial) allergies in adults and children who are at least 6 months old. Xyzal is also used to treat itching and swelling caused by chronic urticaria in adults and children who are at least 6 months old.

Xyzal (Levocetirizine) dosage. Take this medication exactly as prescribed by your doctor. Follow the directions on your prescription label carefully. The recommended dose of Xyzal for adults and children aged 12 years and older is 5 mg once daily in the evening. The recommended dose of Xyzal for children aged 6 to 11 years is 2.5 mg once daily in the evening. Your dosage will be based on your age, medical condition, and response to treatment.