Aminocaproic acid

Mechanism of action

Aminocaproic acid (Acidum aminocapronicum) features a unique dual mechanism aimed at inhibiting fibrinolysis and preserving the blood clot.

1. Activation blockade: The drug binds to plasminogen. This interaction reliably blocks the plasminogen activation process and prevents its conversion into the active enzyme — plasmin.
2. Direct inhibition: The agent exerts a direct inhibitory effect on already formed plasmin. It prevents its contact with fibrin, protecting the fibrin clot from enzymatic cleavage (lysis).

Thus, the blood clot retains its structure, which is critical for stopping bleeding. A structural analogue of the drug, aminomethylbenzoic acid (Amben), has a similar mechanism of action.

Indications for use

The primary goal of prescribing the drug is to stop bleeding caused by excessive, pathological activity of the fibrinolytic system. In clinical practice, this condition occurs in the following situations:

• Surgery and traumatology: extensive trauma, surgical interventions on organs rich in plasminogen activators.
• Obstetrics and gynecology: pathological labor accompanied by coagulopathy, as well as menorrhagia.
• Urology: bleeding associated with prostatitis.
• Gastroenterology: severe liver diseases. In hepatic impairment, the synthesis of both blood coagulation factors and natural fibrinolysis inhibitors is disrupted, requiring drug correction.
• Toxicology and intensive care: specific therapy for overdose of fibrinolytic agents (thrombolytics).

Side effects

The use of aminocaproic acid may be accompanied by a number of adverse reactions that require medical monitoring:

• Cardiovascular system: arterial hypotension, bradycardia, and various arrhythmias may develop. The risk of cardiovascular complications increases if the intravenous administration rate is not respected.
• Gastrointestinal tract: dyspeptic disorders, including nausea and diarrhea.
• Central nervous system: patients may complain of dizziness.

Note: In modern practice, it should be taken into account that other synthetic analogues, such as tranexamic acid (Tranexamic acid), surpass aminocaproic acid in clinical efficacy and have a longer duration of action.

Dosage forms and administration features

The drug is available in two main forms, allowing it to be used both systemically and locally:

• Powder for oral administration.
• Solution in vials (5% — 100 ml) for intravenous administration.

Dosing regimens:

• Oral (per os): prescribed at 2.0–3.0 g.
• Parenteral: administered intravenously by drip. The recommended infusion rate is 50–60 drops per minute, which minimizes the risk of cardiovascular side effects (hypotension and arrhythmias).

Class and exam questions

What else to study on this topic

• Tranexamic acid: differences in pharmacodynamics and safety profile.
• Aprotinin as an inhibitor of proteolytic enzymes (plasmin, etc.).
• Pathophysiology of the fibrinolytic system (plasminogen, plasmin, fibrin).
• Features of hemostasis in severe liver diseases.
• Antidote therapy for fibrinolytic overdose.

Other topics in the «Drugs and Prescriptions» section

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