Anticoagulant

Anticoagulants, commonly known as blood thinners, are chemical substances that prevent or reduce coagulation of blood, prolonging the clotting time. Some of them occur naturally in blood-eating animals such as leeches and mosquitoes, where they help keep the bite area unclotted long enough for the animal to obtain some blood. As a class of medications, anticoagulants are used in therapy for thrombotic disorders. Oral anticoagulants (OACs) are taken by many people in pill or tablet form, and various intravenous anticoagulant dosage forms are used in hospitals. Some anticoagulants are used in medical equipment, such as sample tubes, blood transfusion bags, heart–lung machines, and dialysis equipment. One of the first anticoagulants, warfarin, was initially approved as a rodenticide. Anticoagulants are closely related to antiplatelet drugs and thrombolytic drugs by manipulating the various pathways of blood coagulation. Specifically, antiplatelet drugs inhibit platelet aggregation (clumping together), whereas anticoagulants inhibit specific pathways of the coagulation cascade, which happens after the initial platelet aggregation but before the formation of fibrin and stable aggregated platelet products. Common anticoagulants include warfarin and heparin. The use of anticoagulants is a decision based upon the risks and benefits of anticoagulation. The biggest risk of anticoagulation therapy is the increased risk of bleeding. In otherwise healthy people, the increased risk of bleeding is minimal, but those who have had recent surgery, cerebral aneurysms, and other conditions may have too great a risk of bleeding. Generally, the benefit of anticoagulation is prevention of or reduction of progression of a thromboembolic disease. Some indications for anticoagulant therapy that are known to have benefit from therapy include: Atrial fibrillation — commonly forms an atrial appendage clot Coronary artery disease Deep vein thrombosis — can lead to pulmonary embolism Ischemic stroke Hypercoagulable states (e.g.