Zyrtec is a brand name for the medication cetirizine, which belongs to a class of drugs called antihistamines. It is used to relieve symptoms associated with allergies, such as sneezing, itching, watery eyes, and runny nose. It can also be used to treat symptoms of hives, such as itching and swelling.

Zyrtec works by blocking the effects of histamine, a substance that is released by the body in response to allergens, and causes the symptoms of an allergic reaction.

Zyrtec is available in various forms such as tablets, chewable tablets, and syrup. It is typically taken orally, with or without food, and the dosage will depend on the patient's age, medical history, and the severity of their symptoms. It is important to follow the instructions of a healthcare professional when taking Zyrtec.

Common side effects of Zyrtec include drowsiness, dry mouth, and dizziness. In rare cases, more severe side effects may occur, such as difficulty breathing, swelling of the face, tongue or throat, and a rapid or irregular heartbeat. If any of these symptoms occur, medical attention should be sought immediately.

Zyrtec is available over the counter and is generally considered safe for most people to use. However, it is important to talk to a healthcare professional before taking Zyrtec if you have any medical conditions or are taking any other medications.