Warfarin linked to more bleeding in brain

CINCINNATI, Sept. 30 (UPI) -- People who take the blood thinning drug warfarin may have larger amounts of bleeding in the brain and increased risk of death, U.S. researchers said.

Study author Dr. Matthew L. Flaherty of the University of Cincinnati said warfarin is commonly prescribed to prevent blood clotting to prevent heart attacks. Studies have shown it helps prevent ischemic stroke for patients with an abnormal heart rhythm called atrial fibrillation. However, if the drug makes the blood too thin, it can increase the risk of brain hemorrhage, a type of stroke caused by bleeding in the brain.

The study involved 258 people who had brain hemorrhage, 51 of whom were taking warfarin. Participants were 69 years old on average. The group underwent brain scans to confirm the type of stroke and to measure the size of the blood clots.

The study, published in the medical journal Neurology, found that people who took warfarin and suffered a brain hemorrhage while their international normalized ratio was above 3 had about twice as much initial bleeding as those not taking warfarin. However, this wasn't seen in people whose blood was less likely to clot as determined by an international normalized ratio of less than 3. An international normalized ratio test measures the blood's ability to clot.