- The subject requires concomitant treatment, in therapeutic doses, with anticoagulants such as warfarin or warfarin-related agents, heparin, thrombin or factor Xa inhibitors, or antiplatelet agents (e.g., clopidogrel); low dose aspirin (=< 81 mg/day), low-dose warfarin (=< 1 mg/day), and prophylactic low molecular weight heparin (LMWH) are permitted