Drugs affecting coagulation

•Anticoagulants do not break down existing clots; they prevent clots from forming. •The parenteral anticoagulant heparin and the oral anticoagulant warfarin are used in treating thrombus or thromboembolic disorders to prevent extension of the clot or formation of an embolism. They are also used in high-risk patients to prevent formation of an initial clot. Patients may be taking both drugs at the same time during dose regulation of warfarin. •Low-molecular-weight heparins are administered subcutaneously daily. They have been found to be effective for the same conditions as infusions of heparin. They require less monitoring of blood clotting times, because they have a very predictable effect. Patients can be taught to selfadminister the SC injection at home. •Education for patients taking anticoagulant therapy should include safety measures to prevent bleeding, instructions to be alert for signs of bleeding, and directions for what to do if bleeding occurs. •Antiplatelet drugs prevent platelet aggregation and thereby prevent thrombus formation. They are used prophylactically to prevent CVAs (also called strokes) and MIs (alsocalled heart attacks). They are used as part of treatment for ischemic strokes, after thrombolytic therapy. •Hemorheologic agents promote the fl exibility of the RBCs and decrease blood viscosity to prevent thrombus formation. •Thrombolytic drugs break down existing clots. They are used in acute medical emergencies, such as evolving MI, pulmonary embolism, and acute ischemic stroke. Although they can save lives, these drugs carry a risk for inducing hemorrhage. The patient must be closely monitored during this drug therapy. •Clotting factors are administered when the patient has a defi ciency of clotting factors resulting from heredity or disease. These drugs allow natural clotting to occur and prevent massive blood loss. •Hemostatics are drugs used to promote blood coagulation. Hemostatics come in systemic and topical forms. Systemic hemostatics also interfere with the breaking down of clots.