- Requires concomitant treatment, in therapeutic doses, with anticoagulants such as warfarin or warfarin-related agents, heparin, thrombin or FXa (coagulation factor X) inhibitors, or antiplatelet agents (eg, clopidogrel). Low dose aspirin (above low dose levels for cardioprotection per local applicable guidelines), low-dose warfarin (≤ 1 mg/day), and prophylactic low molecular weight heparin are permitted.