Zyrtec isn’t the first prescription drug to make the switch to over-the-counter (OTC) availability.  But when McNeil launched the OTC version of its allergy medication in January 2008, Zyrtec’s prescription-to-OTC transition was hardly “typical,” according to a new analysis by NielsenHealth and Wolters Kluwer Health.
In the first six months following its launch (January to June 2008), Zyrtec OTC shook up prescription and OTC allergy medication markets in the U.S.   Prescription allergy drug sales declined sharply, while over-the-counter allergy drug sales increased significantly.
By June 2008, prescription sales of Zyrtec had declined to nearly …