This is a generic product sold under its chemical name "ceterizine".
Zyrtec is an antihistamine. It is prescribed to treat the sneezing; itchy, runny nose; and itchy, red, watery eyes caused by seasonal allergies such as hay fever. Zyrtec also relieves the symptoms of year-round allergies due to dust, mold, and animal dander. This medication is also used in the treatment of chronic itchy skin and hives.