|
||
|
American Journal of Medicine
|
|
|
||
|
American Journal of Medicine
|
As reviewed in the previous slide, either UFH or LMWH represent effective initial treatments for VTE, and many physicians will have continued to use these as the “standard of care” for initial therapy.
In most cases, this initial heparin treatment is overlapped with a vitamin K antagonist (VKA, eg, warfarin). What is the evidence that a VKA will work? And why should treatment switch from heparin to the VKA?
The answer to the second question is obvious, because LMWH and fondaparinux must be given by injection, whereas a VKA has been the only oral anticoagulant treatment available until very recently. Moreover there is compelling evidence that VKA is effective. A meta-analysis of eight trials (Figure 6) showed clear evidence that long-term treatment with a VKA is effective for the prevention of recurrence, preventing it or reducing the risk by close to 70 - 80%.[4] On the other hand, one of the penalties with VKA therapy is an excess of bleeding, although is part of the treatment risk with any anticoagulant that there is always a risk of bleeding. Eikelboom J. Am J Med 2013; published on-line at http://education.amjmed.com/00000.
[4] Hutten BA, Prins MH. Duration of treatment with vitamin K antagonists in symptomatic venous thromboembolism. Cochrane Database Syst Rev. 2006;(1):CD001367. DOI: 10.1002/14651858.CD001367.pub2.