Indirect factor Xa inhibitor

Indirect factor Xa inhibitors are a class of anticoagulant drugs that decrease blood coagulation by selectively inhibiting factor Xa via an antithrombin-dependent mechanism. The prototype agent, fondaparinux, is a synthetic pentasaccharide that binds tightly to antithrombin III, greatly enhancing its ability to inhibit factor Xa, thus preventing thrombin generation and fibrin clot formation. These drugs do not affect platelet aggregation directly. Indirect factor Xa inhibitors are clinically used for prevention and treatment of venous thromboembolism, deep vein thrombosis, and to improve survival following myocardial infarction. Compared to direct inhibitors, they only inhibit free factor Xa (not Xa within clots or the prothrombinase complex), and require the presence of antithrombin for their effect.

Other names

Indirect FXa inhibitorIndirect factor Xa antagonistAntithrombin-dependent factor Xa inhibitorHeparin-like inhibitor of factor Xa

Selective inhibition of factor Xa by enhancing antithrombin III's inhibition of factor Xa. Prevents conversion of prothrombin to thrombin, reducing fibrin clot formation.