Used to treat allergy symptoms such as sneezing, runny nose, itchy or watery eyes, and hives. It is an antihistamine that works by blocking histamine, a substance in the body that causes allergic reactions. (R)-Cetirizine is the active enantiomer of cetirizine, providing the same relief at potentially lower doses with fewer side effects like drowsiness. It is commonly found in oral tablets, syrups, and dissolvable forms for quick action. Often used for both seasonal and year-round allergies, including allergic rhinitis and chronic urticaria.