Anticoagulants are drugs with anti-coagulant function, which are commonly used clinically for the prevention and treatment of various thrombotic diseases. The following anticoagulants are commonly used clinically: i. Anti-platelet coagulation drugs, commonly used are aspirin, dipyridamole, clopidogrel, etc., often used in the prevention and treatment of acute myocardial infarction, acute cerebral thrombosis and other diseases. Second, bicoumarins, the most commonly used is warfarin, which can block the absorption of vitamin K and reduce the synthesis of vitamin K-related coagulation factors, and is often used clinically in patients after heart valve surgery, while the international standardized index is often used as the basis for dose adjustment. Third, heparin drugs, which can inactivate the activity of coagulation factor II and coagulation factor X and play an anticoagulant effect, widely used in clinical applications, often used in the treatment of dispersive intravascular coagulation and other diseases.