Aminocaproic acid (also known as ε-aminocaproic acid, ε-Ahx, or 6-aminohexanoic acid; brand name Amicar) is a derivative of lysine, meaning that it acts as an amino acid analogue and can alter functionality of enzymes that require lysine residue binding (e.g. amino acid transporters such as the SLC3A2/SLC7A6 proteins, fibrin, tissue-type plasminogen activator, apolipoprotein(a), aldehyde oxidase, etc.). After oral or intravenous administration, it reaches the bloodstream and can act at the site of vascular injury (or other cause of excess bleeding) where the coagulation (i.e. blood clotting) takes place. Aminocaproic acid is an antifibrinolytic drug. Antifibrinolytics drugs are commonly used during major surgery to prevent significant blood loss (e.g. a liver transplant). By reversibly blocking the binding sites on plasminogen, aminocaproic acid creates a ‘blockade’ in the process of fibrinolysis - this blockade inhibits plasminogen binding to fibrin and the conversion of plasminogen to plasmin (a proteolytic enzyme), preventing fibrin degradation to maintain the stability of fibrin mesh/clots formed through the coagulation cascade. Thus, it reduces clot breakdown and can treat acute bleeding due to elevated fibrinolysis. An orphan drug FDA-approved to prevent recurring hemorrhage in certain patients, aminocaproic acid is also used off-label to control bleeding in patients with immune or nonimmune severe thrombocytopenia (bleeding disorder due to low platelet count). Unlike many other antifibrinolytics, it has no serious side effects at therapeutic doses and there is no evidence that suggests an increased risk of thrombosis.

Aminocaproic Acid Drug Action Pathway (New) References