- The subject requires concomitant treatment, in therapeutic doses, with anticoagulants such as warfarin or Coumadin-related agents, heparin, thrombin or FXa inhibitors, and antiplatelet agents (eg, clopidogrel). Low dose aspirin (≤ 81 mg/day), low-dose warfarin (≤ 1 mg/day), and prophylactic Low Molecular Weight Heparin (LMWH) are permitted.