Monitoring the anticoagulant effect after a massive rivaroxaban overdose.

Rivaroxaban is a direct factor Xa inhibitor approved for prevention of stroke, prevention and treatment of venous thromboembolism and secondary prevention of acute coronary syndrome in many countries. As the use of this agent increases, so does the potential for overdose, both intentional and unintentional. Clinical data on overdoses of rivaroxaban in humans are limited. We report the case of a 42-year-old man who took an overdose of 1400 mg of rivaroxaban and describe how resolution of the anticoagulant effect was monitored using readily available coagulation assays.