Over the past several years, there has been a dramatic increase in the use of the new oral anticoagulants (Dabigatran, Rivaroxaban, and Apixaban). The popularity of these medications stems not only from aggressive pharmaceutical monitoring to physicians and to the general public, but also numerous trials that have demonstrated an equivalent rate of major bleeding, including intracranial hemorrhage, compared with warfarin.[1], [2], [3], [4], [5] Furthermore, the use of these medications does not require regular lab monitoring which is attractive to consumers, unlike the need for INR monitoring with warfarin.
The new oral anticoagulants work by a different mechanism than warfarin. Dabigatran (Pradaxa) is an oral direct thrombin inhibitor so it blocks both the conversion of fibrinogen to fibrin and also blocks the activation of factors V, VII, and IX. Rivaroxaban (Xarelto) and Apixaban (Eliquis) are factor Xa inhibitors that block the conversion of prothrombin to thrombin, which in turn blocks the activation of factors V, VII, and IX.[6]
The drawback to these new oral anticoagulants is that there is no true antidote that can reverse the anticoagulant activity in the event that a patient develops a major hemorrhage or if they require emergency surgery or have a need for an invasive bedside procedure. In general, patients should have the dabigatran held for 24 hours prior to low-risk surgery or an invasive procedure if they have a CrCl >50 mL/min and held for 48 hours if they have a CrCl 30-50 mL/min or will have a high-risk surgery or lumbar puncture. If the CrCl is less than 30 mL/min, Dabigatran should be held for 4 days prior to an invasive procedure and up to 6 days prior to a lumbar puncture. Both rivaroxaban and apixaban should be held for 24 hours prior to a low-risk surgery or an invasive procedure for a CrCl >30 mL/min and held for 48 hours for high-risk surgery, lumbar puncture or for a CrCl <30 mL/min. For patients who have a CrCl <30 mL/min, rivaroxaban and apixaban should be held for 4 days prior to a lumbar puncture.6
These are wonderful guidelines for elective procedures, but how often is a bedside procedure elective? Almost never is the answer. If a bedside procedure needs to be done and the patient has recently taken a new oral anticoagulant drug, the best option is to give four-factor prothrombin complex concentrate 50 IU/kg IV prior to the procedure.[7], [8]
References:
[1] N Engl J Med 2009; 361:1139-1151
[2] N Engl J Med 2009;361:2342-2352.
[3] N Engl J Med 2012;366:1287-1297.
[4] N Engl J Med 2011; 365:883-891
[5] N Engl J Med 2011; 365:981-992
[6] Clev Clinic J of Med. 2013; 80 (7): 443-451.
[7] Thromb Haemost. 2012; 108:217-224.
[8] Circulation. 2011; 124:1573-1579.