- Anticoagulant
- Any agent used to prevent the formation of blood clots. Anticoagulants have various uses. Some are used for the prophylaxis (prevention) or the treatment of thromboembolic disorders. Thrombi are clots. Emboli are clots that break free, travel through the bloodstream, and lodge therein. The anticoagulant drugs used for these clinical purposes include: {{}}Intravenous heparin — which acts by inactivating thrombin and several other clotting factors required for a clot to form; Oral anticoagulants such as warfarin and dicumarol — which act by inhibiting the liver's production of vitamin K dependent factors crucial to clotting. Anticoagulant solutions are also used for the preservation of stored whole blood and blood fractions. These anticoagulants include heparin and acid citrate dextrose (commonly called ACD). Anticoagulants are also used to keep laboratory blood specimens from clotting. These agents include not only heparin but also several agents that make calcium ions unavailable to the clotting process and so prevent the formation of clots; these agents include ethylenediaminetetraacetic acid (commonly called EDTA), citrate, oxalate and fluoride.
* * *- lupus a. antiphospholipid antibody causing elevation in partial thromboplastin time; associated with venous and arterial thrombosis.
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an·ti·co·ag·u·lant .ant-i-kō-'ag-yə-lənt, .an-.tī- adj of, relating to, or utilizing anticoagulants <\anticoagulant therapy>anticoagulant n a substance (as a drug) that hinders coagulation and esp. coagulation of the blood: blood thinner* * *
n.an agent that prevents the clotting of blood. The natural anticoagulant heparin directly interferes with blood clotting and is active both within the body and against a sample of blood in a test tube. Synthetic drugs, such as warfarin, are effective only within the body, since they act by affecting blood coagulation factors. They take longer to act than heparin. Anticoagulants are used to prevent the formation of blood clots or to break up clots in blood vessels in such conditions as thrombosis and embolism. Incorrect dosage may result in haemorrhage. See also fibrinolytic.* * *
an·ti·co·ag·u·lant (an″te-) (an″ti-ko-agґu-lənt) 1. preventing blood clotting. 2. an agent that prevents blood clotting; see anticoagulant therapy, under therapy.
Medical dictionary. 2011.
