Aminocaproic Acid (Amicar)

By | 2013-07-18

Fibrinolysis Inhibitor/Antiprotease

Highlights Of Prescribing Information

May be useful for treating degenerative myelopathies in dogs; efficacy not well documented

Treatment may be very expensive, especially with large dogs

Contraindicated in DIC

Infrequently causes GI distress

What Is Aminocaproic Acid Used For?

Aminocaproic acid has been used as a treatment to degenerative myelopathy (seen primarily in German shepherds), but no controlled studies documenting its efficacy were located. There is interest in evaluating aminocaproic acid for adjunctive treatment of thrombocytopenia in dogs, but efficacy and safety for this purpose remains to be investigated. In humans, it is primarily used for treating hyperfibrinolysis-induced hemorrhage.

Pharmacology/Actions

Aminocaproic acid inhibits fibrinolysis via its inhibitory effects on plasminogen activator substances and via some antiplasmin action. Aminocaproic acid is thought to affect degenerative myelopathy by its antiprotease activity thereby reducing the activation of inflammatory enzymes that damage myelin.

Pharmacokinetics

No pharmacokinetic data was located for dogs.

In a study where 70 mg/kg doses were given IV to horses over 20 minutes, the drug was distributed rapidly and plasma levels remained above the proposed therapeutic level of 130 mcg/mL for one hour after the end of the infusion. Elimination half-life was 2.3 hours. The authors proposed that a constant rate infusion of 15 mg/ kg/hr after the original infusion would maintain more prolonged therapeutic levels ().

In humans, the drug is rapidly and completely absorbed after oral administration. The drug is well distributed in both intravascular and extravascular compartments and penetrates cells (including red blood cells). It is unknown if the drug enters maternal milk. It does not bind to plasma proteins. Terminal half-life is about 2 hours in humans and the drug is primarily renally excreted as unchanged drug.

Before you take Aminocaproic Acid

Contraindications / Precautions / Warnings

Aminocaproic acid is contraindicated in patients with active intravascular clotting. It should only be used when the benefits outweigh the risks in patients with preexisting cardiac, renal or hepatic disease.

Adverse Effects

In dogs treated, about 1% exhibit clinical signs of GI irritation. It potentially can cause hyperkalemia particularly in renal impaired patients.

Reproductive / Nursing Safety

Some, but not all, animal studies have demonstrated teratogenicity; use when risk to benefit ratio merits. In humans, the FDA categorizes this drug as category C for use during pregnancy (Animal studies have shown an adverse effect on the fetus, hut there are no adequate studies in humans; or there are no animal reproduction studies and no adequate studies in humans.)

Overdosage / Acute Toxicity

There is very limited information on overdoses with aminocaproic acid. The IV lethal dose in dogs is reportedly 2.3 g/kg. At lower IV overdosages, tonic-clonic seizures were noted in some dogs. There is no known antidote, but the drug is dialyzable.

How to use Aminocaproic Acid

Aminocaproic Acid dosage for dogs:

For adjunctive treatment of degenerative myelopathy (seen primarily in German shepherds):

a) In combination with exercise, vitamin support (vitamin B-complex, vitamin E), and analgesia (if required; using acetaminophen): Aminocaproic acid: 500 mg (regardless of size of animal, approximate dose is 15 mg/kg) PO q8h. Mix 192 mL of the 250 mg/mL injection with 96 mL of hematinic compound (e.g., Lixotinic) producing a 288 mL final volume. Give 3 mL per dose (500 mg). Store solution in refrigerator. Clinical improvement seen within 8 weeks. ()

b) Aminocaproic acid 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 (0.25-0.5 mg/kg PO daily for 10 days then every other day), Vitamin C (1000 mg PO q12h) and Vitamin E (1000 Int. Units PO ql2). Note: No treatment has been shown to be effective in published trials. ()

As an antifibrinolytic:

a) No published doses for dogs, but has been used anecdotally at 50-100 mg/kg IV or PO q6h. ()

Client Information

■ Aminocaproic Acid costs to treat a German shepherd-sized dog can be substantial

■ As no well controlled studies have documented that this drug is effective for treating degenerative myelopathy, its use should be considered investigational

Chemistry / Synonyms

An inhibitor of fibrinolysis, aminocaproic acid is a synthetic monamino carboxylic acid occurring as a fine, white crystalline powder. It is slightly soluble in alcohol and freely soluble in water and has pKa’s of 4.43 and 10.75. The injectable product has its pH adjusted to approximately 6.8.

Aminocaproic acid may also be known as: acidum aminocaproicum, CL-10304 CY-116, EACA, epsilon aminocaproic acid, JD-177, NSC-26154, Amicar, Capracid, Capramol, Caproamin, Caprolisin, Epsicaprom, Hemocaprol, Hemocid, Hexalense, or Ipsilon.

Storage / Stability/Compatibility

Products should be stored at room temperature. Avoid freezing liquid preparations. Discoloration will occur if aldehydes or aldehydic sugars are present. When given as an intravenous infusion, normal saline, D5W and Ringer’s Injection have been recommended for use as the infusion diluent.

Dosage Forms / Regulatory Status

Veterinary-Labeled Products: None

The ARCI (Racing Commissioners International) has designated this drug as a class 4 substance. See the appendix for more information.

Human-Labeled Products:

Aminocaproic Acid Tablets: 500 mg & 1000 mg; Amicar (Xanodyne); Aminocaproic Acid (VersaPharm); (Rx)

Aminocaproic Oral Solution: 250 mg/mL in 237 mL & 473 mL; Aminocaproic Acid (VersaPharm); (Rx)

Aminocaproic Syrup: 250 mg/mL in 473 mL; Amicar (Xanodyne); (Rx)

Aminocaproic Acid Injection for Intravenous Infusion: 250 mg/mL in 20 mL vials; generic; (Rx)