A new study published in todayÃ¢â‚¬â„¢s edition of the journal Neurology has raised serious safety concerns about the blood-thinning drug warfarin. According to researchers at the University of Cincinnati College of Medicine, the drug may lead to an increased risk of a brain hemorrhage, especially among the older population.
Ã¢â‚¬Å“The rate of brain hemorrhages associated with blood-thinning drugs quintupled during the 1990s,Ã¢â‚¬Â says the American Academy of Neurology, the organization that publishes the journal. Ã¢â‚¬Å“In people over age 80, the rate increased more than tenfold.Ã¢â‚¬Â
Warfarin has proven to be successful in the prevention of blood clots among people with atrial fibrillation (AF), a disorder in which the heartÃ¢â‚¬â„¢s two atria (small upper chambers) donÃ¢â‚¬â„¢t beat effectively. As a result, blood may tend to pool and clot. According to the American Heart Association (AHA), roughly 2.2 million Americans suffer from atrial fibrillation, and about 15 percent of all strokes occur in people with the condition. The likelihood of developing atrial fibrillation increases with age. Three to five percent of people over 65 have atrial fibrillation.
Thanks to its rate of success, warfarin is the preferred anticoagulant for treating AF and has soared in popularity during the past decade because of it. The AHA claims that long-term use of warfarin in patients with AF can reduce incidents of stroke by as much as 68 percent, although they acknowledge that warfarin may bring side effects including potential bleeding problems or ulcers.
However, the new study contends that warfarin, while still effective in preventing certain types of strokes, may actually increase the risk of intracerebral brain hemorrhage, a type of stroke caused by bleeding in the brain. Researchers discovered that in 1988, the rate of these types of hemorrhages associated with blood thinners was only .8 cases per 100,000 people. In 1999, the rate had jumped to 4.4 cases per 100,000 people. For those 80 and older, the rate skyrocketed from 2.5 in 1988 to 45.9 in 1999. The results are attributed in large part to the significant increase in warfarin prescriptions.
Ã¢â‚¬Å“Warfarin is highly effective in preventing ischemic stroke among people with atrial fibrillation,Ã¢â‚¬Â notes lead author Dr. Matthew L. Flaherty. Ã¢â‚¬Å“For many people, the benefits of preventing ischemic stroke continue to outweigh the risk of a hemorrhagic stroke.
Ã¢â‚¬Å“Our findings should not discourage the use of warfarin when itÃ¢â‚¬â„¢s appropriate. Doctors can use these findings to make sure they are weighing the risks and benefits of warfarin use for their patients. For researchers, these results may stimulate efforts to develop safer alternatives to warfarin and better treatments for people with brain hemorrhages.Ã¢â‚¬Â