Researchers at the University of Cincinnati (UC) published a report indicating that increased use of the anticoagulant warfarin is the main reason for a significant rise in the number of brain hemorrhages in the 1990s. Warfarin is commonly prescribed to thin a patient’s blood in order to prevent ischemic strokes, the most common form of strokes, which are often triggered by blood clots that cut off a critical supply of nutrients and oxygen to the brain.
“Warfarin use increased during the 1990s, because it was proven to be effective in preventing ischemic strokes among people who have an abnormal heart rhythm called atrial fibrillation,” said Matthew L. Flaherty, MD, lead author of the study and a neurologist at UC.
Flaherty and his fellow researchers collected clinical data on all patients in the greater Cincinnati area who had been admitted to the hospital after experiencing a first-time brain hemorrhage in the years 1988, 1993-1994 and 1999. The data showed substantial increases in warfarin-related bleeding in the brain. In 1988, among all study participants, the annual rate of intracerebral hemorrhages associated with warfarin was 0.8 cases per 100,000 people. By 1999 the rate had risen to 4.4 cases per 100,000 patients. Among patients 80 years old and older, the rate increased significantly from 2.5 in 1988 to 45.9 in 1999.
In light of their findings, the UC scientists explained that although warfarin can be an effective treatment for some patients, doctors need to take a more prudent approach when deciding whether to prescribe it.
“Some of those patients are better off being on warfarin," said Flaherty. "The message isn't that no one should use warfarin. There needs to be a balance between the benefit of preventing ischemic stroke and the risk of bleeding.”
One example of how doctors could make better decisions regarding warfarin, asserts Flaherty, would be to employ the International Normalized Ratio (INR), a blood test that measures a patient’s blood clotting capacity. It could be given on a regular basis to determine if an individual is more susceptible to bleeding.
Other researchers have also acknowledged the test’s utility. “In Europe, they are doing home monitoring,” said Michael B. Rothberg, Associate Professor of Medicine at Tufts University School of Medicine. “Like patients who monitor their own blood sugar, there are patients who monitor their own INR.”
While Flaherty admits that warfarin is still the best drug for preventing ischemic strokes in certain patients, he says he looks forward to the day when safer treatments will be available.
The report, “The Increasing Incidence of Anticoagulant-Associated Intracerebral Hemorrhage,” was published in the January 9, 2007 issue of the journal Neurology.
Source: HealthDay News, January 8, 2007