Zertazine is a brand name for the medication that contains Cetirizine, an antihistamine used to treat allergy symptoms like a runny nose, sneezing, itchy eyes, and hives. It's commonly used for conditions like hay fever (allergic rhinitis) and chronic urticaria (hives). A 10 mg dose is a common amount for adults and children over 6 years of age. It can help relieve symptoms of seasonal allergies or allergic reactions, as well as conditions like itchy skin due to allergies. Cetirizine works by blocking the action of histamine, a substance in the body that causes allergic symptoms.