Development of tinzaparin: a heparinase-digested low-molecular-weight heparin.

Although heparin and its properties had been discovered in the early 1920s, the different characteristics associated with different molecular-weight fractions of heparin were only recognized in the late 1970s. Tinzaparin is a low-molecular-weight heparin (LMWH) produced by heparinase digestion of heparin. Preclinical research on tinzaparin established that there were no differences in the antithrombotic activity compared with heparin. Clinical studies evaluating tinzaparin vs. standard heparin for thromboprophylaxis of deep-vein thrombosis in general and orthopedic surgery found that tinzaparin was as effective as standard heparin. Tinzaparin was also evaluated vs. standard heparin in the treatment of acute proximal vein thrombosis; time-to-event curves suggested that this LMWH could be more effective than standard heparin.