Effectiveness and safety of bemiparin versus low-molecular weight heparins in orthopaedic surgery

Bemiparin

Bemiparin (bemiparin sodium; Hibor, Ivor, Zibor, Badyket) is a low molecular weight heparin (LMWH) with a lower mean molecular weight (3600 D) and a higher anti-Xa/IIa ratio (8:1) than other LMWHs. Bemiparin was effective as thromboprophylaxis in surgical patients in well controlled clinical trials. No cases of venous thromboembolism (VTE) were reported in low- to moderate-risk patients receiving prophylaxis with bemiparin 2500 anti-Xa IU/day for 7 days or unfractionated heparin (UFH) 5000 anti-Xa IU twice daily for 7 days. In high-risk patients, bemiparin 3500 anti-Xa IU/day for > or =8 days was more effective than UFH 5000 anti-Xa IU twice daily for > or =8 days in the prevention of VTE in patients undergoing total hip replacement. Postoperative bemiparin 3500 anti-Xa IU/day for 10 days was as effective as enoxaparin 4000 anti-Xa IU/day for 10 days commenced 12 hours before surgery in high-risk patients undergoing total knee replacement. As a short-term treatment for acute established deep vein thrombosis (DVT), bemiparin 5000-10 000 anti-Xa IU/day (dependent on bodyweight) for 7 or 10 days was more effective than intravenous UFH (5000 anti-Xa IU bolus followed by 30,000 or 40,000 anti-Xa IU/day for 7 days) in reducing thrombus size from baseline. Bemiparin 3500 anti-Xa IU/day was also as effective as oral warfarin (10 mg/day for the first 3 days, then adjusted to achieve an international normalised ratio between 2 and 3) for the long-term (12 weeks) treatment of DVT, although data are limited. Subcutaneous bemiparin was generally well tolerated. The most commonly reported adverse events in clinical trials were postoperative bleeding complications (similar incidence to that with UFH or enoxaparin in high-risk patients, lower incidence in low- to moderate-risk patients).

CONCLUSIONS

Bemiparin is a new LMWH which has shown efficacy in a small number of well controlled trials in the prevention of postoperative VTE in low- to moderate- and high-risk patients and in the treatment of established DVT. It can be initiated pre- or post-operatively, whereas recommendations for other LMWHs in Europe primarily involve preoperative initiation. Additional comparative studies would be beneficial in determining the overall place of bemiparin, particularly with respect to the relative incidence of bleeding complications. In the meantime, available data suggest that bemiparin is an effective and useful addition to the available range of LMWHs for the prevention of VTE and treatment of DVT.