NEW YORK (AP) _ Under immense regulatory and competitive pressure, Schering-Plough Corp. said Friday it planned to switch its blockbuster allergy prescription medicine Claritin to an over-the-counter drug.
The switch means the company's top selling drug will see its sales shrivel, analysts say. Last year, Claritin had sales of $2.7 billion. That could sink to $400 million next year if the switch is approved as expected.
Analysts said the company has little choice.
Late last year, an FDA advisory panel said Claritin and two competing products _ Pfizer's Zyrtec and Aventis' Allegra _ were safe enough to be sold over-the-counter.
The FDA, which has said it agrees with the panel's finding, is expected to make that determination official in a few weeks. What remains unclear is whether the FDA would force the companies to switch the products to over-the-counter sales, and if it has the power to do so.
Schering-Plough is under more pressure than Pfizer or Aventis because Claritin is it largest selling drug and it is expected to lose patent protection in December.
The Kenilworth, N.J.-based company has already filed numerous lawsuits against generic firms seeking to bring a cheaper version of Claritin to market.
Even more threatening, analysts said, are applications filed with the FDA by rivals Johnson & Johnson and American Home Products to market generic over-the-counter versions of Claritin, which could have frozen Schering out of the market if it didn't act.
Schering said Friday it had filed an application with the FDA to switch the brand to over-the-counter and expects to have a drug on the market by November.
Schering introduced Clarinex, a successor to Claritin, late last year in a bid to extend its franchise. However, analysts say Clarinex isn't a vast improvement over its predecessor so insurance companies may not reimburse patients for a more expensive prescription drug with only marginal benefits when an over-the-counter remedy will suffice.
``That drug is going to face significant hurdles,'' said Dr. Girish Tyagi, an analyst at ABN Amro Inc.