Determination of anticoagulant activity of direct oral anticoagulants: the current state of knowledge and a single center experience

Direct oral anticoagulants (DOACs) increasingly replace vitamin K antagonists in the treatment and prevention of venous thromboembolism, and stroke prevention in non-valvular atrial fibrillation. Due to their predictable pharmacological mechanism, no diet restrictions and lack of interaction with most drugs, DOACs do not require routine laboratory monitoring. However, in cases of suspected concentrations beyond the expected range or a need for an emergent surgical procedure, access to laboratory methods for reliable DOACs determination is necessary. In a routine laboratory, the anticoagulant effect of dabigatran can be determined using methods based on ecarin or the modified dilute thrombin time. Rivaroxaban, apixaban and edoxaban may be measured using the chromogenic anti-FXa assays. Our own experience (the longest in Poland) from the John Paul II Hospital laboratory with the 24-hour availability of DOACs measurement involves determinations of dabigatran (n = 136), rivaroxaban (n = 374) and apixaban (n = 22) in outpatients and hospitalized patients between May 2013 and April 2017. Determination of the level of DOACs should be available 24/7 in highly specialized medical centers, especially in those which perform emergency procedures for treating patients with acute stroke and hemorrhages.