Enoxaparin sodium belongs to low molecular weight heparin, which is a new anticoagulant drug developed in the 1970s. It is a short chain preparation of ordinary heparin prepared by chemical separation method, with an average molecular weight of 1 to 12KD.

　　Compared with ordinary heparin, enoxaparin sodium has the following characteristics:

　　1. The inhibitory effect on factor Xa and factor XIIa was stronger than that on factor IIa, and the effect on platelet was small;

　　2, the anticoagulant effect is strong, ordinary heparin is often inhibited by platelet factor 4, but low molecular weight heparin is not;

　　3, long half-life, high bioavailability. Its half-life is 200 to 300 minutes, two to four times longer than that of regular heparin. 4. There are few bleeding complications, and generally no need to monitor anticoagulant activity.

　　Sodium heparin is a sodium salt of glucosamine sulfate extracted from the intestinal mucosa of pigs. It is a mucosaccharide substance and plays an anticoagulant effect by activating antithrombin ⅲ (AT-ⅲ). Heparin sodium has an effect on the three stages of the coagulation process, and has an anticoagulant effect in vitro and in vivo. It can prolong the clotting time, prothrombin time and thrombin time.