Pathophysiology
Clinical meaning
Anticoagulant medications prevent thrombus formation and propagation by interfering with the coagulation cascade. Heparin (unfractionated) acts by potentiating antithrombin III to inactivate thrombin and factor Xa. Low-molecular-weight heparins (enoxaparin) preferentially inhibit factor Xa. Warfarin inhibits vitamin K-dependent clotting factor synthesis (II, VII, IX, X). Direct oral anticoagulants (DOACs) directly inhibit thrombin (dabigatran) or factor Xa (rivaroxaban, apixaban). These medications carry significant bleeding risk. The nurse monitors for signs of bleeding, administers medications as ordered, and reports abnormal findings to the RN.