Aprotinin (AP)

Aprotinin  is used as medication administered by injection to reduce bleeding during complex surgery, such as heart and liver surgery. Its main effect is the slowing down of fibrinolysis, the process that leads to the breakdown of blood clots. The aim in its use is to decrease the need for blood transfusions during surgery, as well as end-organ damage due to hypotension (low blood pressure) as a result of marked blood loss. The drug was temporarily withdrawn worldwide in 2007 after studies suggested that its use increased the risk of complications or death; this was confirmed by follow-up studies.

Aprotinin is a monomeric (single-chain) globular polypeptide derived from bovine lung tissue; it has a molecular weight of 6512 and consists of 16 different amino acids arranged in a chain of 58 amino acid residues.