Factor Xa inhibitor drugs
Factor Xa inhibitor drugs are used to prevent DVT in patients un-dergoing total hip and knee replacement surgery or surgery to re-pair a hip fracture. The only factor Xa inhibitor drug used in the United States is fondaparinux.
Administered subQ, fondaparinux is absorbed rapidly and com-pletely and is excreted primarily unchanged in urine. Its effects peak within 2 hours of administration and last for about 17 to 24 hours.
Fondaparinux binds to antithrombin III and greatly influences the neutralization of factor Xa by antithrombin III. Neutralization of factor Xa interrupts the coagulation cascade, thereby inhibiting clot formation.
Fondaparinux is used only to prevent the formation of blood clots.
Avoid administering fondaparinux with another drug that may increase the risk of bleeding. (See Adverse reactions to factor Xa inhibitors.)