Zyrtec is an antihistamine medication containing 10mg of cetirizine dihydrochloride per tablet. These film-coated tablets are manufactured by GSK and come in a pack of 20 tablets. The medication is used to relieve allergy symptoms like 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. The medication typically starts working within one hour and can provide 24-hour relief from allergy symptoms when taken as directed.