Anticoagulants are drugs used to prevent the formation of blood clots, reducing the risk of stroke, heart attack and pulmonary embolism. Heparin and warfarin are used to inhibit the formation and growth of existing thrombi, with the former used for acute anticoagulation while the latter is used for long-term anticoagulation. The mechanism of action of heparin and warfarin are different as they work on different pathways of the coagulation cascade. Heparin works by binding to and activating the enzyme inhibitor antithrombin III, an enzyme that acts by inactivating thrombin and factor Xa. In contrast, warfarin works by inhibiting vitamin K epoxide reductase, an enzyme needed to synthesize vitamin K dependent clotting factors II, VII, IX, and X. Bleeding time with heparin and warfarin therapy can be measured with the partial thromboplastin time (PTT) and prothrombin time (PT), respectively.
Thrombus
Thrombosis
Abscess
Enema
Thrombocythemia
Platelet plug
Embolus
Hernia