Impax and Andrx sued by S-P over Claritin infringement

Schering-Plough has filed lawsuits against Impax Laboratories and AndrxCorp for alleged patent infringement of its blockbuster antihistamine Claritin (loratadine). The suit against Impax relates to the company's recent filing with the US Food and Drug Administration for a generic version of S-P's Claritin-D 24-Hour (loratadine/pseudoephedrine sulfate) extended-release tablets, which had sales of about $400 million in the 12 months ended September 30, 2000.

Impax' chief executive, Barry Edwards said that while the firm believes the S-P move is without merit, "we are not surprised it was filed," noting that a lawsuit such as this "is a routine means by which branded pharmaceutical manufacturers attempt to extend marketing exclusivity of a product, while maintaining high prices." It has been estimated that in the next five years, patent protection will be lost on branded drugs with more than $35 billion in annual sales. Similarly, Andrx, which is being sued over its generic version of Claritin Reditabs, sees the lawsuits as a delaying tactic.