US generic drugmaker Barr Pharmaceuticals says that it has agreed to pay $22.5 million to settle a lawsuit with Novartis subsidiary Sandoz over access to the widely-used anticoagulant medicine warfarin.

The action, which was brought against Barr in 1998 by Invamed and Apothecon (both of which are now owned by Sandoz), claimed that the firm was in violation of antitrust laws and illegally blocking access to the raw material source for warfarin sodium.

In 2004, the US Court of Appeals ruled that the plaintiffs had raised issues of material fact on their antitrust claims, scheduling a trial date of June 12 this year.

Prior to commencement of the trial, Barr agreed to make a one-time settlement payment in order, it said, to avoid incurring further defense costs, although it insisted that the litigation was ‘without merit’.