Barr Labs Launches First Generic Warfarin In USA

Barr Laboratories has launched the first generic version of DuPontMerck's anticoagulant Coumadin (warfarin sodium) in the USA, following the product's March approval by the Food and Drug Administration (Marketletter April 7). The launch is accompanied by a $5 million marketing campaign aimed at pharmacists, doctors and patients, and trumpets the efforts made by the generic industry to help control health care costs.

DuPont Merck has responded to the threat by issuing a statement attempting to cement loyalty to its branded product, saying that the launch should serve as "a warning bell to physicians and patients who have relied on Coumadin for many years." At stake is a market for the drug thought to be worth about $500 million a year in the USA; Coumadin is the 11th most-prescribed drug in that country, with prescriptions growing 14% annually. Barr is expected to price its version at about 40% less than the brand-name product.

DuPont Merck Reaction DuPont Merck had tried to prevent the approval by changing equivalence standards for the drug. The company has petitioned the FDA to adopt an individual bioequivalence standard for warfarin, rather than the average bioequivalence standard used in the approval process for Barr's product, because warfarin has a very narrow therapeutic index. This has not been successful, and the company is lobbying state legislatures to introduce legislation to prevent generic substitution of narrow therapeutic index drugs.