Factor Xa antagonists are used increasingly frequently for prevention and treatment of venous thromboembolic events and for prevention of stroke and systemic emboli in patients with non-valvular atrial fibrillation. Individual characteristics of patient, a need in prolonged or life-long treatment, concomitant diseases, the use of other drugs interacting with anticoagulants increase the risk of side effects of anticoagulation. We analyzed the current data on the efficacy and safety of Xa factor antagonists, as well as the features of their use in the event of adverse reactions, particularly bleedings. The possibilities of monitoring the efficacy and safety of treatment with these drugs were evaluated.