April 21, 2011

Risky Use of Blood Clotting Drug

(Ivanhoe Newswire) -- Physicians may be misusing and overusing an expensive blood clotting drug, and the practice could be dangerous for patients. The drug known as recombinant factor 7a (RF7a) is intended for hemophilia patients, but a pair of new studies found it's being used predominantly to treat patients who don't have the disorder.

Hemophilia is a rare bleeding disorder in which the blood doesn't clot normally. Studies from the Stanford University School of Medicine estimated that only 4 percent of RF7a use in U.S. hospitals from 2000 through 2008 was for treating hemophilia patients. The remaining 96 percent of the time, the drug was used during heart surgery or to treat trauma, intracranial hemorrhages and other medical problems.

Researchers say while there haven't been many studies done on the safety of the drug's use for other disorders and treatments, the little evidence that does exist reveals it can increase the risk of blood clots, which can lead to heart attacks and strokes. The powerful drug costs about $10,000 per dose.

Researchers say physicians should think twice about giving the drug to anyone other than hemophilia patients. The practice, known as off-label prescribing, is where physicians use medications to treat conditions other than those approved by the FDA. The practice isn't illegal, but since RF7a hasn't been tested for any other uses, researchers warn it could be dangerous.

"Many patients and physicians wrongly assume that the FDA has scrutinized all of the different ways a drug can be used, but they've only examined those uses that have gone through the approval process," senior author Randall Stafford, M.D., Ph.D., associate professor of medicine at the Stanford Prevention Research Center, was quoted as saying.

For the studies, Veronica Yank, M.D., Aaron Logan, M.D., Ph.D., Stafford and their colleagues analyzed data from randomized clinical trials, observational studies, and other databases. They found that heart surgery patients who were given RF7a had a 5 percent higher risk of developing blood clots, and intracranial hemorrhage patients had a 3 percent higher risk of developing clots. They also found that the use of RF7a grew 140-fold between 2000 and 2008, primarily for off-label uses.

Researchers hope the two studies will prompt health providers to be more cautious about the off-label use of RF7a.

SOURCE: Annals of Internal Medicine, April 18, 2011