Heparin, lovenox and warfarin are intravenous, injectable and oral anticoagulant medications that are typically used to thin your blood and slowly break down a leg or lung blood clot. For severe clots, particularly those in your lungs, clot busting medications like tissue plasminogen activator are used to dissolve the clump of blood more quickly. Time Frame Heparin treatment is usually required for up to one week, reports RxList.