Anticoagulant medications work by inhibiting the body's natural clotting process, preventing the formation of new blood clots, and stabilizing existing clots. Usually, anticoagulation therapy is started with low molecular weight heparin for 5-10 days intravenously and later switched on to oral anticoagulants for a prolonged period. In some cases, this can be bypassed by starting with oral anticoagulants, depending upon severity.