In 2002, the Food and Drug Administration (FDA) approved
(fondaparinux), a blood thinner to help prevent the dangerous blood clots that can occur after certain types of surgery.
When a blood clot forms in a vein in the legs, it is called
deep vein thrombosis
(DVT). DVT can block blood flow through the vein. Symptoms include pain, swelling, warmth, and a change in skin color of the affected leg. However, sometimes there are no symptoms unless a clot breaks loose and travels through the bloodstream to the lungs. This is called
, and can be fatal.
People who undergo certain surgeries are at high risk of developing DVT. These include:
As a precautionary measure, these patients are often given blood-thinning drugs after surgery. The most commonly used drugs are
and a group of drugs called low molecular-weight heparins. One example is
Arixtra is the first synthetic drug created to prevent deep vein thrombosis. It is made from the portion of the heparin molecule that inhibits a key factor in blood clotting—activated Factor X. In studies done by the drug's manufacturer of more than 4000 patients, those given Arixtra were 50% less likely to develop a blood clot than those given Lovenox.
However, in this study, Arixtra was given six hours after surgery, while Lovenox was given 18 hours after surgery. The 18-hour mark is the standard time for administration of Lovenox. The FDA pointed out that if both drugs were given after six hours, they may have worked equally as well. Therefore, the FDA approval does not say that Arixtra is superior to standard therapy, but that it is an effective option.
All blood-thinning drugs can cause excessive, dangerous bleeding, and Arixtra is no exception. During clinical trials, the risk of bleeding was greater for certain groups of people, and therefore this drug should not be given to the following:
Those with serious kidney failure
Those who weigh less than 110 pounds
Age >75 years old is listed by the manufacturer, but is not a contraindication
Active major bleeding,
, and patients with thrombocytopenia associated with a positive
test for antiplatelet antibody in the presence of fondaparinux sodium are other contraindications listed by the manufacturer
Please be aware that this information is provided to supplement the care
provided by your physician. It is neither intended nor implied to be a
substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER
IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the
advice of your physician or other qualified health provider prior to
starting any new treatment or with any questions you may have regarding a