Novel oral anticoagulants for atrial fibrillation.

Warfarin reduces the risk of stroke in patients with non-valvular atrial fibrillation but has limitations: a narrow therapeutic window, the need for regular monitoring, and risks of bleeding and drug-drug interactions. Partly because of these limitations, novel oral anticoagulants (NOACs or non-vitamin K antagonists) have emerged, including direct thrombin inhibitors.