Zyrtec is an antihistamine medication containing 10mg of Cetirizine dihydrochloride per tablet. It comes in a pack of 20 film-coated tablets and is manufactured by GSK to provide relief from allergy symptoms like hay fever, sneezing, runny nose and itchy eyes. As a prescription medication, Zyrtec should be taken according to your healthcare provider's instructions. The film coating makes the tablets easier to swallow while protecting the active ingredient. This product contains cetirizine dihydrochloride which works by blocking histamine, a substance in the body that causes allergic symptoms.