WASHINGTON (AP) -- The popular allergy drug Zyrtec-D can now sell without a prescription, the Food and Drug Administration announced Friday. Zyrtec-D combines the antihistamine cetirizine with a nasal decongestant, pseudoephedrine. It is for use by adults and children 12 or older to relieve symptoms of hay fever and other respiratory allergies. Like other brands that contain pseudoephedrine, nonprescription Zyrtec-D will be sold from behind store counters because of a new law that requires customers to show identification, among other steps, before buying the decongestant. The law is intended to limit purchases of large quantities of pseudoephedrine, which can be used to cook the illegal drug methamphetamine.