April 14, 2009

Anti-clot drugs linked to brain bleeding

People who take aspirin or other drugs that prevent blood clotting appear more likely to have tiny areas of bleeding in the brain, Dutch researchers said.

Dr. Meike W. Vernooij and colleagues at Erasmus MC University Medical Center in Rotterdam, the Netherlands, investigated the relationship between cerebral microbleeds and the use of anti-clotting medications in 1,062 individuals without dementia involved in the Rotterdam Scan Study.

Participants, who were an average age 69.6, underwent magnetic resonance imaging examinations in 2005 and 2006. Pharmacy records were used to assess whether any of the individuals took anti-clotting drugs such as aspirin and other anti-clotting drugs.

In the years before MRI, 34.2 percent of the participants had used anti-clotting drugs. Compared with patients who didn't use anti-clotting drugs, those who took aspirin or carbasalate calcium were more likely to have cerebral microbleeds visible on MRI.

This association was particularly strong among individuals taking these drugs at higher doses, typically used to treat or prevent heart disease. Microbleeds in the frontal lobe were more common among aspirin users than carbasalate calcium users -- platelet aggregation inhibitors that prevent the accumulation of platelets that form blood clots. There was no association between other types of anti-clotting drugs and cerebral microbleeds.

The findings are published online ahead of print in the June issue of Archives of Neurology.