Introduction
An antifibrinolytic agent that acts by inhibiting plasminogen activators which have fibrinolytic properties.
Uses
Aminocaproic acid is an antifibrinolytic agent used to induce clotting postoperatively.
For use in the treatment of excessive postoperative bleeding.
Associated Conditions
Pharmacodynamics
Aminocaproic acid works as an antifibrinolytic. It is a derivative of the amino acid lysine. The fibrinolysis-inhibitory effects of aminocaproic acid appear to be exerted principally via inhibition of plasminogen activators and to a lesser degree through antiplasmin activity. Aminocaproic acid may be a possible prophylactic for vascular disease, as it may prevent formation of lipoprotein (a), a risk factor for vascular disease.
Mechanism of Action
Aminocaproic acid binds reversibly to the kringle domain of plasminogen and blocks the binding of plasminogen to fibrin and its activation to plasmin. With NO activation of plasmin, there is a reduction in fibrinolysis. This consequently will reduce the amount of bleeding post surgery. Elevated plasma levels of lipoprotein(a) have been shown to increase the risk of vascular disease. Lipoprotein 9a)a has two components, apolipoprotein B-100, linked to apolipoprotein (a). Aminocaproic acid may change the conformation of apoliprotein (a), changing its binding properties and potentially preventing the formation of lipoprotein (a).
Absorption
Absorbed rapidly following oral administration. In adults, oral absorption appears to be a zero-order process with an absorption rate of 5.2 g/hr. The mean lag time in absorption is 10 minutes. After a single oral dose of 5 g, absorption was complete (F=1).
Volume of Distribution
- 23.1 ± 6.6 L
Route of Elimination
Renal excretion is the primary route of elimination, whether aminocaproic acid is administered orally or intravenously.
Half Life
The terminal elimination half-life is approximately 2 hours.
Clearance
- 169 mL/min
Toxicity
A few cases of acute overdosage with intravenous administration have been reported. The effects have ranged from no reaction to transient hypotension to severe acute renal failure leading to death. The intravenous and oral LD50 were 3.0 and 12.0 g/kg respectively in the mouse and 3.2 and 16.4 g/kg respectively in the rat. An intravenous infusion dose of 2.3 g/kg was lethal in the dog.
Food Interactions
- Take with or without food. The absorption is unaffected by food.
Dosage
Aminocaproic acid is equally effective by mouth and intarvenous injection. In cases of particular severity, or when it is sought to obtain a high blood concentration quickly it is advisable to start treatment by intravenous rough, with slow injection of two Aminocaproic acid ampules with an interval of 30-60 minutes between them, continuing with divided doses until a dosage of 20-25 grams in the 24 hour is reached.
In any case, administration of the drug must be continued until complete cessation of all symptoms. Aminocaproic acid could be intravenously administered, following suitable dilution in Physiological solution.
