Trasylol is an injectable prescription drug which inhibits certain enzymes that increase the risk of bleeding during surgery and aids the body's ability to prevent bleeding. Normally, the drug is given to patients undergoing heart bypass surgery to control blood loss, but has also been used in other surgeries, such as hip replacement surgery. Trasylol is manufactured by Bayer Pharmaceuticals Corporation and was approved by the Food and Drug Administration in December 1993 to reduce bleeding and the need for blood transfusion in patients undergoing heart surgery.

In November 2007, pressured by regulators around the world, the drug's manufacturer, Bayer A.G. announced that it had agreed to withdraw the controversial heart surgery drug after a Canadian study suggested that it increased death rates. The FDA has asked for a phased withdrawal of the drug, because of concerns that alternative medicines could run short.  On May 14, 2008, Bayer Pharmaceuticals notified the U.S. Food & Drug Administration (FDA) that they would be initiating a nationwide Trasylol recall. Trasylol use has been linked to increased risk of death, kidney or renal failure, heart attacks, strokes and encephalopathy among heart surgery patients.