Saturday, August 26, 2006

Heparin vs. Enoxaparin for Venous Thrombosis

Perhaps the biggest piece of news in cardiovascular circles this week was the JAMA article demonstrating the equivalency of unfractionated heparin to low-molecular-weight heparins, like enoxaparin (Lovenox) in treating patients with deep venous thrombosis (blood clots in the legs). This study spells trouble for Sanofi Aventis, the maker of Lovenox. Why? Because of hospitals' concerns over pharmaceutical costs. One dose of 5000 units of heparin costs $1.15, where one dose of a 40mg syringe of Lovenox costs hospitals about $24. Granted the usual starting dose of heparin in this study was about 26,000 units (320 U/kg), with 20,000 units (250U/kg) given twice a day, whereas the average daily dose of Lovenox was 8290 units, but this still represents a significant cost savings for hospitals if this drug substitution is widely adopted by the medical community. And since this study was performed without the requirement for follow-up assessment of the partial thromboplastin time (or PTT) blood levels and demonstated an equal safety record, it likely will be adopted in future guidelines for anticoagulation therapy for deep venous thrombosis.

It would be interesting to re-run all of the retrospective studies funded and eventually marketed by Sanofi Aventis with the newer, more aggressive heparin dosing guidelines adopted by the authors of the currrent JAMA article to re-evaluate costs.

Look for more studies comparing plain ol' heparin at higher doses to enoxaparin for other indications (like pulmonary embolus, acute coronary syndromes and the like) in the future.


1 comment:

Anonymous said...

Three qurters of the patients recieving Low Molecular Weight heparin in this study recieved Fragmin. Fragmin has a lower anti XA:IIA ratio than Enoxaparin and hence is much more heparin-like. This probably explains the similarity between both study groups.