Apixaban (Eliquis) directly inhibits factor Xa by interfering with the conversion of prothrombin to thrombin and preventing the formation of cross-linked fibrin clots.
Edoxaban (Lixiana, Savaysa) is a selective Xa inhibitor. Edoxaban inhibits free Xa without the need for antithrombin. This inhibition of Xa in the coagulation cascade leads to decreased thrombin generation and a reduction in thrombus formation. The reduction in thrombin also results in indirect inhibition of platelet aggregation.
Rivaroxaban (Xarelto) is a small molecule that binds directly and reversibly to factor Xa. Rivaroxaban competitively inhibits Factor Xa and is greater than 10,000-fold more selective for factor Xa than other related serine proteases. It does not require cofactors (such as antithrombin) to exert its anticoagulant effect.
Unlike indirect factor Xa inhibitors, rivaroxaban inhibits both free and clot-bound factor Xa and prothrombinase activity, thereby prolonging clotting times.
