Aminocaproic Acid
**Aminocaproic acid (EACA)** is a synthetic derivative of the amino acid lysine. It acts as a **fibrinolysis inhibitor** and **antiprotease**. * **Historical Veterinary Use**: It has been used as an adjunctive treatment for **degenerative myelopathy (DM)** in dogs (especially German Shepherds), though modern evidence strongly questions its efficacy for this condition. Studies have shown no neurological improvement, and its use for DM is largely considered investigational and unrewarding. * **Primary Clinical Use**: Its primary, evidence-based use is in the management of **hyperfibrinolysis-induced hemorrhage**. It is increasingly used in veterinary medicine to prevent or treat severe bleeding disorders, trauma, or surgical bleeding (e.g., in Greyhounds, which are highly predisposed to delayed postoperative hemorrhage). * **Thrombocytopenia**: There is ongoing interest in evaluating its use as an adjunctive treatment for severe thrombocytopenia in dogs to prevent fatal bleeding, though safety and efficacy are still being investigated.
Mechanism: Aminocaproic acid is a lysine analog that competitively binds to the lysine-binding sites on **plasminogen**. * **Plasminogen** → (blocked by EACA) → Cannot bind to fibrin. * This prevents the conversion of plasminogen to **plasmin** by plasminogen activators. * At higher concentrations, it directly inhibits **plasmin** (antiplasmin activity), thereby preventing the breakdown of fibrin clots (**fibrinolysis**). * *In Degenerative Myelopathy*: It was theorized to exert **antiprotease activity**, reducing the activation of inflammatory enzymes that damage myelin, though clinical efficacy is lacking.
Dosing by species
- Adjunctive treatment of degenerative myelopathy (seen primarily in German shepherds) · 500 mg/dog · PO · q8h · indefinitely · Used in conjunction with acetylcysteine at 25 mg/kg PO q8h for 2 weeks, then q8h every other day. The 20% solution should be diluted to 5% with chicken broth or suitable diluent. Other treatments may include prednisone, Vitamin C, and Vitamin E. Note: No treatment has been shown to be effective in published trials.
- Antifibrinolytic · 50-100 mg/kg · IV or PO · q6h · No published doses for dogs, but has been used anecdotally.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Routes of administration
Contraindications
- Active intravascular clotting (e.g., Disseminated Intravascular Coagulation - DIC)
Adverse effects
- GI irritation (vomiting, diarrhea) in ~1% of dogs
- Hyperkalemia (particularly in renal impaired patients)
Drug interactions
- Estrogens · Hypercoagulation states may occur in patients receiving aminocaproic acid and estrogens concurrently.
Monitoring
- Serum potassium (especially in patients with preexisting renal failure)
- Signs of bleeding or thrombosis
- Neurological status (if used for degenerative myelopathy)
Overdose
> **Toxicity**: The intravenous lethal dose in dogs is reportedly **2.3 g/kg**. * **Clinical Signs**: At lower IV overdosages, **tonic-clonic seizures** were noted in some dogs. * **Treatment**: There is no known specific antidote, but the drug is dialyzable. Treatment should consist of supportive care and seizure management (e.g., diazepam, midazolam) if necessary.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.