Warfarin sodium is used for the treatment of thromboembolic disease in patients requiring long-term continuous anticoagulation to prevent the formation and progression of thrombosis, for the treatment of venous thrombosis after surgery or trauma, and as an adjunct to myocardial infarction. It can also be used prophylactically in patients with previous thromboembolic disease and in patients with postoperative thrombotic complications. Warfarin is an intermediate-acting anticoagulant of the bicoumarin class, and patients are usually on long-term medication. For patients using warfarin, it is advisable to monitor blood levels frequently. Warfarin sodium can inhibit the synthesis of coagulation factors in hepatocytes, and also has the effect of reducing the thrombin-induced platelet aggregation reaction, so it has anticoagulation and anti-platelet aggregation effects. Care must be taken when using warfarin to pay attention to drug interactions when using other drugs, because there are some drugs that can enhance the anticoagulant effect of warfarin, such as aspirin, salicylic acid, quinidine, indomethacin and so on, so drug interactions belong to a large part of warfarin need to pay attention to the content.