Aminocaproic Acid: Prescribing Guidelines
When to Prescribe
Aminocaproic acid should be prescribed when there is documented hyperfibrinolysis or significant bleeding that persists despite standard hemostatic measures, particularly in trauma, surgical bleeding, or hematologic malignancy-related hemorrhage. 1
Primary Indications
- Major trauma with ongoing bleeding: Consider as adjunctive therapy when bleeding continues despite surgical control and blood product replacement 1
- Documented hyperfibrinolysis: Confirmed by shortened euglobulin clot lysis time (<120 minutes) or laboratory evidence of excessive fibrinolytic activity 1, 2
- Refractory thrombocytopenia with bleeding in hematologic malignancy patients 3
- Hemophilia patients with inhibitors: Excellent adjuvant therapy, particularly for postoperative bleeding or mucosal hemorrhage 4
Critical Prerequisite
Do NOT administer aminocaproic acid without definite diagnosis and/or laboratory findings indicative of hyperfibrinolysis. 2 The drug should only be used when there is clear evidence of excessive fibrinolytic activity, not as empiric therapy for all bleeding.
How to Prescribe: Dosing Regimens
Standard Loading and Maintenance Dosing
Loading dose: 150 mg/kg IV followed by continuous infusion of 15 mg/kg/hour 1
- For a 70 kg patient: 10.5 g loading dose, then 1.05 g/hour infusion
- The elimination half-life is 60-75 minutes, requiring continuous infusion to maintain therapeutic levels 1
Alternative Dosing Regimens
Oral dosing: 5 g initially, then 1-1.25 g/hour (or 5 g every 6 hours) to achieve plasma levels of 0.13 mg/mL needed for fibrinolysis inhibition 2
High-dose regimen: Up to 5 g bolus has been used safely in some studies 1
Duration of Therapy
Continue the infusion until bleeding is adequately controlled, then discontinue promptly. 1 Do not continue beyond the point of hemostasis to minimize thrombotic risk 1
Critical Safety Considerations
Thrombotic Risk
- Theoretical concern exists for precipitated thrombosis, though large studies (>8,000 patients) showed no increased arterial or venous thrombotic events 1
- Do NOT administer with Factor IX Complex concentrates or Anti-Inhibitor Coagulant concentrates due to increased thrombosis risk 2
- Intravascular clotting cases were likely due to underlying conditions (e.g., DIC) rather than the drug itself 2
Platelet Dysfunction at High Doses
Doses exceeding 24 g/day prolong bleeding time and inhibit platelet function. 5 At concentrations ≥7.4 mMol/L (0.97 mg/mL), aminocaproic acid inhibits platelet aggregation 2, 5
- Patients on >24 g/day experienced prolonged bleeding times (>20 minutes in many cases) and increased rebleeding 5
- Monitor with serial bleeding time tests if using high doses 5
- Keep total daily dose ≤24 g/day to avoid platelet dysfunction 5
Renal Impairment
Reduce dosage in patients with renal failure as aminocaproic acid is renally excreted and accumulates 1 Mild renal impairment typically does not affect outcomes, but significant dysfunction requires dose adjustment 1
Neurological Concerns
Increased incidence of hydrocephalus, cerebral ischemia, or vasospasm reported in subarachnoid hemorrhage, though drug relatedness remains unclear as these are also natural complications of SAH 2
Monitoring Requirements
- Laboratory tests to determine fibrinolysis level: Euglobulin clot lysis time, profibrinolysin, fibrinolysin, and antifibrinolysin levels 2
- Template bleeding time if using doses >24 g/day 2, 5
- Fibrinogen levels: Rising fibrinogen after aminocaproic acid initiation suggests effective control of fibrinolysis 6
- D-dimer levels: Elevated levels suggest ongoing fibrinolysis and may predict response 7
Comparison to Tranexamic Acid
Aminocaproic acid has 10-fold weaker potency than tranexamic acid, requiring proportionally higher doses 1 Tranexamic acid is generally preferred when available due to:
- Longer half-life (120 minutes vs 60-75 minutes) 1
- Lower required doses
- More extensive evidence base in trauma (CRASH-2 trial) 1
However, aminocaproic acid remains a cost-effective alternative, particularly in resource-limited settings or hematologic malignancy 3
Special Populations
Hematologic Malignancy
Aminocaproic acid appears safe and cost-effective for refractory thrombocytopenia with or without bleeding 3 Median duration of use is 6 days, with thrombotic events rare (5.7%) and not clearly drug-related 3
Hemophilia with Inhibitors
Excellent adjuvant therapy that allows substantial reduction in FEIBA or activated prothrombin complex usage 4 Can be used via local, oral, or intravenous routes 4
ECMO Patients
May be effective when high D-dimers and low fibrinogen suggest fibrinolysis 7 Use cautiously given already elevated thrombotic risk in ECMO 7