Review of recently approved alternatives to anticoagulation with warfarin for emergency clinicians.

BACKGROUND

Dabigatran and rivaroxaban are novel anticoagulants that have been approved for the prevention of thromboembolic events in atrial fibrillation. These medications are attractive to both patients and clinicians, as, unlike warfarin, they do not require laboratory monitoring or dietary restrictions. However, they carry bleeding risks similar to that of warfarin and are without a reliable reversal agent.

OBJECTIVES

The objectives of this article are to 1) summarize the pivotal trials leading to the U.S. Food and Drug Administration approvals of dabigatran (Pradaxa; Boehringer Ingelheim, Ridgefield, CT) and rivaroxaban (Xarelto; Janssen Pharmaceuticals, Inc., Titusville, NJ); 2) present the limited data available regarding the management of bleeding patients on these agents; and 3) provide suggestions to guide emergency providers given the limited data.

DISCUSSION

Dabigatran and rivaroxaban were approved based on large, non-inferiority trials comparing the new agents to warfarin with stroke or systemic embolism as the primary outcome. Traditional coagulation studies cannot be used to determine the degree of anti-coagulation produced by these agents. Fresh frozen plasma is unlikely to be effective in patients on these drugs who are acutely bleeding. Prothrombin complex concentrate can be considered in patients on rivaroxaban. Dabigatran is renally cleared, so dabigatran could be removed by hemodialysis. Theoretically, DDAVP (Sanofi-Aventis U.S. LLC, Bridgewater, NJ), aminocaproic acid, tranexamic acid, or recombinant activated factor VII could also be used in an attempt to control bleeding.

CONCLUSION

There is a need for assays for the degree of anticoagulation produced by drugs such as dabigatran and rivaroxaban. Additionally, studies are needed to evaluate reversal agents that could be effective in the setting of acute bleeding.