Aprotinin is a naturally occurring polypeptide protease inhibitor obtained from bovine lung tissue. It works by inhibiting enzymes such as plasmin, trypsin, chymotrypsin, and kallikrein. By blocking plasmin, aprotinin prevents the breakdown of fibrin clots and reduces fibrinolysis. This action helps in decreasing excessive bleeding during surgical procedures. It is mainly used in major surgeries, especially cardiac surgeries like coronary artery bypass grafting (CABG). Aprotinin helps reduce blood loss and lowers the need for blood transfusions. It also decreases inflammation by inhibiting kallikrein activity. Previously, it was used in the treatment of acute pancreatitis to suppress pancreatic enzymes. However, its use became limited due to concerns about kidney damage and increased risk of complications. Today, aprotinin is used under strict medical supervision in selected high-risk surgical cases.
