Brands, Medical Use, Clinical Data
- Solution for injection (containing 250 mg/mL of aminocaproic acid) and tablets (500, 1000mg)
Brands / Synonyms
Acepramin; Acepramine; ACS; Afibrin; Amicar; Amikar; Aminocaproic; Aminocaproic Acid; Aminocaproic Acid In Plastic Container; Aminokapron; Atsemin; Caplamin; Capracid; Capramol; Capranol; Caprocid; Caprolisin; EACA; EACS; Epsamon; Epsicapron; Epsikapron; Epsilcapramin; Epsilcapramine; Hemocaprol; Hemopar; Hepin; Ipsilon; Respramin
For use in the treatment of excessive postoperative bleeding.
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.
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.
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).
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.
Biotrnasformation / Drug Metabolism
Sixty-five percent of the dose is recovered in the urine as unchanged drug and 11% of the dose appears as the metabolite adipic acid.
AMICAR should not be used when there is evidence of an active intravascular clotting process.
When there is uncertainty as to whether the cause of bleeding is primary fibrinolysis or disseminated
intravascular coagulation (DIC), this distinction must be made before administering AMICAR.
The following tests can be applied to differentiate the two conditions:
- Platelet count is usually decreased in DIC but normal in primary fibrinolysis.
- Protamine paracoagulation test is positive in D.C. a precipitate forms when protamine sulphate is dropped into
citrated plasma. The test is negative in the presence of primary fibrinolysis.
- The euglobulin clot lysis test is abnormal in primary fibrinolysis but normal in DIC.
AMICAR must not be used in the presence of DIC without concomitant heparin.
Drug Laboratory Test Interactions
Prolongation of the template bleeding time has been reported during continuous intravenous infusion of AMICAR at
dosages exceeding 24 g/day. Platelet function studies in these patients have not demonstrated any significant
platelet dysfunction. However, in vitro studies have shown that at high concentrations (7.4 mMol/L or 0.97 mg/mL and
greater) EACA inhibits ADP and collagen-induced platelet aggregation, the release of ATP and serotonin, and the
binding of fibrinogen to the platelets in a concentration-response manner. Following a 10 g bolus of AMICAR,
transient peak plasma concentrations of 4.6 mMol/L or 0.60 mg/mL have been obtained. The concentration of AMICAR
necessary to maintain inhibition of fibrinolysis is 0.99 mMol/L or 0.13 mg/mL. Administration of a 5 g bolus followed
by 1 to 1.25 g/hr should achieve and sustain plasma levels of 0.13 mg/mL. Thus, concentrations which have been
obtained in vivo clinically in patients with normal renal function are considerably lower than the in vitro
concentrations found to induce abnormalities in platelet function tests. However, higher plasma concentrations of
AMICAR may occur in patients with severe renal failure.