Symptoms include: sneezing; runny nose; itchy, red, or watery eyes; and itchy nose or throat. Cetirizine is also used to treat the itching and redness of hives. However, cetirizine does not prevent hives or other allergic skin reactions. Cetirizine is in a class of medications called antihistamines. It works by blocking the action of histamine, a substance present in the body that causes allergy symptoms.