Aminocaproic Acid

DESCRIPTION Aminocaproic Acid is 6-aminohexanoic acid, which acts as an inhibitor of fibrinolysis. The structural formula is: NH 2 CH 2 (CH 2 ) 3 CH 2 COOH The molecular formula is: C 6 H 13 NO 2 Molecular Weight: 131.17 Aminocaproic Acid is soluble in water, acid and alkaline solutions; it is sparingly soluble in methanol and practically insoluble in chloroform. Aminocaproic Acid Injection, USP, for intravenous administration, is a sterile pyrogen-free solution containing 250 mg/mL of Aminocaproic Acid with Benzyl Alcohol 0.9%, as a preservative, and Water for Injection q.s. The pH is adjusted to approximately 6.8 with Hydrochloric Acid and/or Sodium Hydroxide.

INDICATIONS AND USAGE Aminocaproic Acid Injection is useful in enhancing hemostasis when fibrinolysis contributes to bleeding. In life-threatening situations, fresh whole blood transfusions, fibrinogen infusions, and other emergency measures may be required. Fibrinolytic bleeding may frequently be associated with surgical complications following heart surgery (with or without cardiac bypass procedures), and portacaval shunt; hematological disorders such as aplastic anemia; acute and life-threatening abruptio placentae; hepatic cirrhosis; and neoplastic disease such as carcinoma of the prostate, lung, stomach, and cervix. Urinary fibrinolysis, usually a normal physiological phenomenon, may frequently be associated with life-threatening complications following severe trauma, anoxia, and shock. Symptomatic of such complications is surgical hematuria (following prostatectomy and nephrectomy) or nonsurgical hematuria (accompanying polycystic or neoplastic diseases of the genitourinary system). (See WARNINGS .)

CONTRAINDICATIONS Aminocaproic acid 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 aminocaproic acid. 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 DIC; a precipitate forms when protamine sulfate 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. Aminocaproic acid must not be used in the presence of DIC without concomitant heparin.

ADVERSE REACTIONS Aminocaproic acid is generally well tolerated. The following adverse experiences have been reported: General : Edema, headache, malaise. Hypersensitivity Reactions : Allergic and anaphylactoid reactions, anaphylaxis. Local Reactions : Injection site reactions, pain and necrosis. Cardiovascular : Bradycardia, hypotension, peripheral ischemia, thrombosis. Gastrointestina l: Abdominal pain, diarrhea, nausea, vomiting. Hematologic : Agranulocytosis, coagulation disorder, leukopenia, thrombocytopenia. Musculoskeletal : CPK increased, muscle weakness, myalgia, myopathy (see WARNINGS ), myositis, rhabdomyolysis. Neurologic : Confusion, convulsions, delirium, dizziness, hallucinations, intracranial hypertension, stroke, syncope. Respiratory: Dyspnea, nasal congestion, pulmonary embolism. Skin : Pruritus, rash. Special Senses : Tinnitus, vision decreased, watery eyes. Urogenital : BUN increased, renal failure. There have been some reports of dry ejaculation during the period of aminocaproic acid treatment. These have been reported to date only in hemophilia patients who received the drug after undergoing dental surgical procedures. However, this symptom resolved in all patients within 24 to 48 hours of completion of therapy.

Pregnancy Pregnancy Category C. Animal reproduction studies have not been conducted with aminocaproic acid. It is also not known whether aminocaproic acid can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Aminocaproic acid should be given to a pregnant woman only if clearly needed.

Pediatric Use Safety and effectiveness in pediatric patients have not been established. Aminocaproic Acid Injection, USP contains benzyl alcohol as a preservative. Benzyl alcohol has been associated with a fatal “gasping syndrome” in neonates. The “gasping syndrome”, characterized by central nervous system depression, metabolic acidosis, gasping respirations, and high levels of benzyl alcohol and its metabolites found in the blood and urine, has been associated with exposure to benzyl alcohol in neonates and low-birth weight neonates. Additional symptoms may include gradual neurological deterioration, seizures, intracranial hemorrhage, hematologic abnormalities, skin breakdown, hepatic and renal failure, hypotension, bradycardia, and cardiovascular collapse (see WARNINGS ).

OVERDOSAGE A few cases of acute overdosage with aminocaproic acid administered intravenously have been reported. The effects have ranged from no reaction to transient hypotension to severe acute renal failure leading to death. One patient with a history of brain tumor and seizures experienced seizures after receiving an 8 gram bolus injection of aminocaproic acid. The single dose of aminocaproic acid causing symptoms of overdosage or considered to be life-threatening is unknown. Patients have tolerated doses as high as 100 grams while acute renal failure has been reported following a dose of 12 grams. The intravenous and oral LD 50 of aminocaproic acid were 3 and 12 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. On intravenous administration, tonic-clonic convulsions were observed in dogs and mice. No treatment for overdosage is known, although evidence exists that aminocaproic acid is removed by hemodialysis and may be removed by peritoneal dialysis. Pharmacokinetic studies have shown that total body clearance of aminocaproic acid is markedly decreased in patients with severe renal failure.