A three-year study of more than 1,000 patients found that the risk of delayed intracranial hemorrhage and death following head trauma was significantly higher for adults taking older blood thinning medications including clopidogrel (Plavix) and warfarin (Coumadin), according to research being presented today at the annual meeting of the Radiological Society of North America (RSNA). Taking aspirin concurrently with any blood thinner may increase the risk of delayed hemorrhage.