COLCHICINE

(for veterinary information only)

BRAND NAME: COLCRYS

AVAILABLE IN,
0.3 mg, 0.5 mg and 0.6 mg TABLETS
AND ORAL SOLUTION

BACKGROUND

Colchicine is a medication with several seemingly unrelated uses and effects. In humans, it is mostly used in the treatment of gout (a metabolic disease where uric acid crystals deposit in joints creating pain). In this condition, it appears to relieve inflammation associated with crystal accumulation but in dogs and cats colchicine is used to reduce scarring processes such as liver cirrhosis and abnormal protein deposition such as amyloidosis. Colchicine stimulates enzymes called collagenases which break down collagen protein (the structural proteins that make up scars) and inhibits liver cells from making amyloid A (an abnormal protein that destructively infiltrates other organs especially the kidney - see below).

Colchicine interferes with cell division by interfering with the formation of "mitotic spindles," the protein cables that pull the dividing cells apart.

HOW THIS MEDICATION IS USED

In veterinary medicine, is generally used once a day. It may be given with or without food. Common diseases in pets that commonly involve colchicines treatment are:

• Shar-pei Recurrent Fever Syndrome (also called “Swollen Hocks Syndrome” or "Shar Pei Auto Inflammatory Disease")
  This condition is named for the fevers and accompanying ankle swelling but the part of the syndrome that is actually harmful is the deposition of abnormal protein called “Amyloid” in the kidney. Renal amyloidosis leads to protein loss in urine, including numerous blood proteins that keep one alive. Because the risk of amyloid development is the same regardless of the number of fever episodes, it has been recommended that colchicine treatment begin as soon as the the condition is diagnosed. That said, if the disease has progressed into actual kidney insufficiency, it is too late for colchicine to be helpful.
  
• Hepatic Cirrhosis
  In this condition, the normal cells of the liver die and are replaced by scar tissue. This leads to a small, hard, shrunken, ineffective liver. As a general rule, once scarring has occurred, the damage is permanent but colchicine seems to have some ability to reverse scarring in addition to preventing its formation.

Veterinary experience with colchicine is limited to dogs.

SIDE EFFECTS

Because of colchicine’s ability to interfere with cell division, it should not be used in animals for breeding. It is not only harmful to unborn young but will also reduce sperm production.

The chief side effect is nausea. Often a low dose is started to see if the patient tolerates the drug and if no problems occur with vomiting, diarrhea, or appetite loss then the dose is raised to a more therapeutic level.

Also, because of colchicine’s ability to interfere with cell division, there has been some concern about bone marrow toxicity. Since many dogs, particularly Shar-peis, are on this drug for years on end, it is prudent to consider periodic blood testing to check the white and red blood cell counts.

The use of colchicine may cause a urine dip stick to falsely read positive for blood. The use of colchicine can also increase the alkaline phosphatase level as read on a blood chemistry panel.

Colchicine can deplete the body of vitamin B-12 (cobalamin) in some cases. Check with your veterinarian to see if supplementation, either oral or injectable, is a recommended for your pet.

INTERACTIONS WITH OTHER DRUGS

Drugs that have bone marrow side effects (particularly chemotherapy agents and the antibiotic chloramphenicol) may increase the potential for bone marrow issues. Side effects of colchicine are more likely to become evident with concurrent use of the "azole" antifungal medicines (ketoconazole, itraconazole, fluconazole etc.)

Concurrent use of colchicine and cyclosporine (an immunomodulator), diltiazem (used in heart disease), or erythromycin (an antibiotic) can increase the potential for kidney damage and bone marrow suppression.

CONCERNS AND CAUTIONS

Colchicine tablets should be stored at room temperature and kept away from light exposure.

If a dose is accidentally skipped by more than 8 hours, simply pick up with the next scheduled dose. Do not double up on doses.

Colchicine cannot be used in pregnancy and is probably best not used in animals intended for breeding.

Colchicine should not be used in pregnancy as it interferes will cell division. It should not be handled by pregnant women. Urine from treated animals may also pose a hazard to pregnant women.

In 2010, the FDA granted URL Pharma sole rights to produce colchicine as their own brand name product. This action removed all generics from the market, dramatically increased the price of colchicine, and created a drug availability crisis. At this time options for purchase of colchicine include:

• Brand name Colcrys
• Colchicine from a compounding pharmacy
• Colchicine from a Canadian pharmacy

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Page last updated: 1/11/2026