Coumadin takes weeks to start having an effect, but Exanta begins working in two hours, like heparin.

FORBES: Magazine Article

Nevertheless, doctors wrote 21 million prescriptions for the anti-coagulant Coumadin (generically known as warfarin), a drug growing 5% a year.

FORBES: The Plot Thickens

But Coumadin's capacity to interact with everything from spinach to supplements was expected to be a major selling point for the new drug.

FORBES

European studies unveiled at the American College of Cardiology meeting indicate that Exanta works at least as well as the current treatment, Coumadin, for preventing stroke.

FORBES: Magazine Article

In the meantime, DuPont AIDS drug Sustiva fits in with Bristol's two HIV treatments, and DuPont anti-coagulant Coumadin meshes with Bristol's existing heart drugs, even though no patent protects it.

FORBES: The New Bristol-Myers

Barr also targeted AZT, Coumadin and Premarin.

FORBES: Lawyers In Lab Coats

For 60 years, doctors have had only one pill to prevent clotting: warfarin, a drug originally derived from rat poison and sold under the brand name Coumadin by Bristol-Myers Squibb (nyse: BMY - news - people ).

FORBES: Replacing Coumadin