Aminocaproic acid

Aminocaproic acid (also known as Amicar, є-amino caproic acid, or 6-aminohexanoic acid) is a derivative and analogue of the amino acid lysine, which makes it an effective inhibitor for enzymes which bind that particular residue. Such enzymes include proteolytic enzymes (which break down proteins) including plasminogen, the enzyme responsible for fibrinolysis. For this reason it is effective in treatment of some bleeding disorders and is marketed as Amicar.

Mechanism of action
Aminocaproic acid works as an anti-fibrinolytic or anti-proteolytic. As a lysine analogue, it binds reversibly to the kringle domain of the enzyme plasminogen and blocks binding of fibrin, which is normally activated to plasmin.

Clinical use
Aminocaproic acid is used to treat excessive postoperative bleeding. It can be given orally or intravenously. One scenario where it may be useful is to treat bleeding after dental extractions in patients with hemophilia, because the oral mucosa is rich in plasminogen activators. A meta-analysis found that lysine analogs like aminocaproic acid significantly reduced blood loss in patients undergoing coronary artery bypass grafting.

Side effects
Its side effects are mainly related to the gastrointestinal tract and include nausea, vomiting, abdominal pain, and diarrhea. It may cause generalised myalgia. The main risk associated with aminocaproic acid is the increased risk for thrombosis because of the inhibition of fibrinolysis.

Other uses
Aminocaproic acid is occasionally used in BN-PAGE buffers, not for its effects as a proteolysis inhibitor, but to solubilize membrane proteins in place of sodium chloride (which is incompatible with PAGE in the necessary concentration). Percent recovery of protein complexes increases linearly with the concentration of inhibitor (between 125 mM and 750 mM).