Colchicine

What is colchicine?

Colchicine (brand names: Colcrys®, Mitigare®, Gloperba®) is an anti-inflammatory drug used to treat amyloidosis and Shar-Pei fever. It has also reportedly been used to treat chronic scarring of the liver.

In birds, it has also reportedly been used to treat hyperuricemia. Its use in veterinary medicine is largely experimental and its effectiveness has not been well documented.

Its use in dogs and birds to treat amyloidosis, hepatic fibrosis, hyperuricemia, and Shar-Pei fever is off label (extra label). Many drugs are commonly prescribed for off-label use in veterinary medicine. 

“Off label” means the drug is being used in a way that has not been reviewed or approved by the U.S. Food and Drug Administration (FDA) or Health Canada. In these instances, follow your veterinarian’s directions and cautions carefully, as they may be significantly different from those on the label.

How is colchicine given?

• Colchicine is given by mouth in the form of a tablet or capsule. It may also be compounded into a liquid form.
• Measure liquid forms carefully.
• Do not crush or split tablets, or open capsules.
• Colchicine may be given with or without food.
• If your pet vomits when dosed on an empty stomach, give future doses with food.
• Wash your hands after giving this medication.
• Do not handle this medication if you are pregnant; wear gloves if handling is necessary. 

This medication should take effect within 1 to 2 hours; however, effects may not be visible, so laboratory tests may be needed to evaluate this medication’s effectiveness.

What if I miss giving my pet the medication?

If you miss a dose, give it as soon as you remember, and then wait the recommended time as prescribed by your veterinarian for the next dose. Do not give the pet two doses at once.

Are there any potential side effects?

Side effects may include:

• Mild nausea
• Vomiting
• Diarrhea

Serious side effects include:

• Lack of appetite
• Severe or persistent vomiting
• Diarrhea
• Skin rash
• Incoordination
• Severe tiredness
• Weakness
• Infections
• Bleeding
• Bruising

Other side effects may occur. If you notice anything unusual, contact your veterinarian immediately. This moderate-acting medication should stop working in a few days, although effects can be longer in pets with liver or kidney disease.

Are there any risk factors for this medication?

DO NOT use colchicine in pets that:

• Are allergic to it
• Have severe kidney, gastrointestinal, or heart disease

USE WITH CAUTION in pets that:

• Are old, weak, frail, pregnant or lactating,
• Have mild kidney, gastrointestinal, or heart disease

Studies are limited, and there may be other risk factors that have not been documented.

Are there any drug interactions I should be aware of?

Several medications should be used with caution when given with colchicine, including:

• Amphotericin B
• Antineoplastics
• Azole antifungals
• Chloramphenicol
• Cyclosporine
• Diltiazem
• Erythromycin
• Immunosuppressants

Certain medications may interact with colchicine, so be sure to tell your veterinarian about any medications (including vitamins, supplements, or herbal therapies) that your pet is taking before starting any new treatment.

Is any monitoring needed with this medication?

• Your veterinarian may monitor a complete blood count and cobalamin levels, particularly when using this medication long term.
• Your veterinarian may monitor your pet to be sure that the medication is working.
• At home, monitor for any side effects such as those noted above. If any side effects occur, stop using the medication and contact your veterinarian.

How do I store colchicine?

• Store colchicine at room temperature and keep it protected from light.
• Compounded formulations should be stored according to the label on the bottle.

What should I do in case of emergency?

If you suspect an overdose or an adverse reaction to the medication, call your veterinary office immediately. If they are not available, follow their directions in contacting an emergency facility. Be prepared to provide information about the product and your pet’s weight and symptoms.