Active Ingredient: Compare to the active ingredient of Zyrtec. Cetirizine Hydrochloride, an antihistamine, is approved for the treatment of both indoor and outdoor allergy symptoms. 24-Hour Allergy Relief: Each tablet temporarily provides relief of symptoms due to hay fever or other upper respiratory allergies, including itchy, watery eyes; runny nose; sneezing and itching of the nose or throat. Indoor & Outdoor Allergy Relief: Kirkland Signature Aller-Tec temporarily relieves common indoor and outdoor...