Warfarin thrombus formation

Finally, aspirin has also been used to prevent thrombus formation in peripheral veins (deep vein thrombosis [DVT]), and aspirin is sometimes used as an adjunct or alternative to anticoagulants (heparin, warfarin) that are routinely used to treat DVTs.8 Aspirin can likewise be administered to prevent thromboembolism following surgical procedures such as coronary artery bypass, arterial grafts, endarterectomy, and valve replacement 45,78 By preventing platelet-induced thrombogenesis, aspirin helps maintain patency and prevent reocclusion of vessels following these procedures. 

Normal hemostasis is a balance between excessive and inadequate blood clotting. Overactive blood clotting is harmful because of the tendency for thrombus formation and occlusion of arteries and veins. Vessels may become directly blocked by the thrombus, or a portion of the thrombus may break off and create an embolism that lodges elsewhere in the vascular system. The tendency for excessive thrombus formation in the venous system is usually treated with anticoagulant drugs such as heparin and warfarin. Platelet inhibitors such as aspirin help prevent arterial thrombogenesis. Thrombolytic drugs (streptokinase, t-PA) that facilitate the dissolution of harmful clots may successfully reopen... 

Warfarin and Phenoharhital. Phenobarbital, by causing enzyme induction, can increase the rate of metabolism of warfarin. The result of this interaction is a decreased response to the anticoagulant and an increased risk of thrombus formation if the interaction is not recognized. 

Anticoagulants and thrombolytics, particularly warfarin, can systemically embolize cholesterol particles from aortic atherosclerotic plaques to small arteries and arterioles, including renal arterioles. These agents remove or prevent thrombus formation over ulcerative plaques, causing emboh. Cholesterol emboli induce an inflammatory obliterative vascular response, causing renal ischemia. Purple discoloration of the toes and mottled skin over the legs are important clinical clues. 

Dicoumarol is found in spoiled sweet clover warfarin is used as a rat poison. Similar antagonists may be used clinically to reduce the probability of blood clotting in patients with a tendency to thrombus formation. Several other clotting factors also contain g-carboxyglutamate and they, too, will be affected by vitamin K antagonists. 

Fondaparinux is a selective inhibitor factor Xa possessing a selective inhibition of antithrombin III (ATIII), which potentiates the innate neutralization of factor Xa by ATIII. Nentralization of factor Xa interrupts the blood coagulation cascade and inhibits thrombin formation and thrombus development. It is indicated for prophylaxis of deep vein thrombosis (DVT) that may lead to pulmonary embolism in patients undergoing hip fracture surgery including extended prophylaxis, hip replacement surgery, or knee replacement surgery. When administered in conjunction with warfarin, fondaparinux is indicated for treatment of acute DVT and acute pulmonary embolism. 

A clot is a thrombus that has formed in an arterial or venous vessel and is caused by decreased circulation (blood stasis). Anticoagulants such as warfarin and heparin inhibit clot formation but do not dissolve clots that have already formed. 

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