Aspirin (650 mg/day) was allowed in the PROWESS trial. Patients on glycoprotein IIb/IIIa inhibitors were excluded because no data were available regarding drug interactions and pharmacokinetics. Use of these types of agents is likely to increase the risk of bleeding with drotrecogin alfa (activated) therapy. The anticipated benefits must therefore be weighed against the potential risks. In the PROWESS trial, efforts were made to correct the international normalized ratio towards normal if it was greater than 3 at any time during infusion of drotrecogin alfa (activated).