Epsilon Aminocaproic Acid - Antifibrinolytic Cardiovascular Poison

Epsilon Aminocaproic Acid

e- Aminocaproic acid is an inhibitor of fibrinolysis, whichis useful in the management of post-partum haemorrhage, haematuria, hereditary angioedema, subarachnoid haemor-rhage, prevention of haemorrhage after dental extraction in haemophiliacs, and prevention of rebleeding following trau-matic hyphaema. It is a synthetic amino acid which is similar in structure to lysine and ornithine.

Aminocaproic acid is readily absorbed from the gastroin-testinal tract. Peak plasma levels are reached within 2 hours of a single oral dose. After prolonged administration, it distributes throughout both the intravascular and extravascular compart-ments. It readily penetrates red blood cells. It does not appear to be bound to plasma proteins. Aminocaproic acid is readily excreted in the urine. 80% of a single dose is excreted in 12 hours.

Side effects include nausea, vomiting, diarrhoea, conjunc-tival hyperaemia, and delirium. Hypotension and bradycardia may be seen after too rapid intravenous administration. Overdose results in rash, vomiting, diarrhoea, myopathy, prolongation of bleeding time, seizures, thrombosis formation, hepatic failure, and acute renal failure. Severe cases of myop-athy may be associated with muscle necrosis, myoglobinuria, rhabdomyolysis, and prolonged elevations of muscle enzymes.

Treatment involves stabilisation and supportive measures. Bleeding time, hepatic function, and renal function should be monitored. Serial bleeding time tests are indicated for patients receiving aminocaproic acid. Myopathy may occur, producing high plasma creatine kinase levels, and mild hyperbilirubinaemia. Serial creatinine phosphokinase (CPK) levels are important in monitoring a patient using aminocaproic acid. This is especially true if the therapy is in excess of 2 weeks and a total dose greater than 500 grams. In general, aminocaproic acid-associated renal failure and myopathy have improved with discontinuation of therapy. Aminocaproic acid can be removed by dialysis.