Colchicine
Also known as: Colcrys · Artrex · Colchily · Colchicquim · Colchis · Colcine · Colgout · Goutichine · Goutnil · Reugot · Ticolcin · Tolchicine · Colchicine · colchicinum
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
🌎 NA — North America🌍 EU — Europe
Dogs
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Adjunctive treatment of hepatic cirrhosis/fibrosis | 0.03 mg/kg PO once daily | PO | q24h | — | 🌎 NA |
| Adjunctive treatment of hepatic cirrhosis/fibrosis | 0.025-0.03 mg/kg PO once daily | PO | q24h | — | 🌎 NA |
| Periodic fever syndrome in Shar Pei dogs | 0.03 mg/kg PO once daily | PO | q24h | — | 🌎 NA |
| To reduce the frequency and severity of fever and prevent the development of amyloidosis in dogs with Shar Pei Fever | 0.025-0.03 mg/kg PO q24h | PO | q24h | — | 🌎 NA |
| Fibrosis / Renal amyloidosis | Initial dose 0.01 mg/kg, increase in incremental amounts every 3-4 days to a maximum dose of 0.03 mg/kg | PO | q24h initially, up to q12h | Long-term | 🌍 EU |
- Adjunctive treatment of hepatic cirrhosis/fibrosis: Probenecid-free drug. Not recommended for initial use with azathioprine, chlorambucil or methotrexate due to similar side effects. Used in many dogs and fewer cats without problems.
- To reduce the frequency and severity of fever and prevent the development of amyloidosis in dogs with Shar Pei Fever: No evidence supports use of colchicine once amyloidosis has resulted in renal failure.
- Fibrosis / Renal amyloidosis: Increase dose only if no adverse GI effects occur.
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Fibrosis | Not recommended | PO | N/A | N/A | 🌍 EU |
- Fibrosis: No evidence for its efficacy as an antifibrotic in cats.
Birds
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| As an antifibrotic for the adjunctive treatment of hepatic fibrosis (Psittacines) | 0.2 mg/kg PO q12h | PO | q12h | — | 🌎 NA |
- As an antifibrotic for the adjunctive treatment of hepatic fibrosis (Psittacines): May potentiate gout in some cases.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Colchicine is a unique, plant-derived alkaloid (from Colchicum autumnale) traditionally known for its antigout properties in human medicine. In veterinary pharmacology, it is utilized primarily as an investigational or off-label therapy for specific fibrotic and inflammatory conditions.
Key veterinary applications include:
- Hepatic Cirrhosis/Fibrosis: Used to slow or reverse fibrotic changes in the liver.
- Shar-Pei Fever (Familial Amyloidosis): Administered to prevent the deposition of amyloid proteins in the kidneys.
- Endotracheal Stent Granulation: Has been used experimentally to treat granulation stenosis following stent placement.
Clinical Pearl: Colchicine has a narrow therapeutic index. Gastrointestinal distress is often the first sign of toxicity and warrants immediate reassessment of the patient.
Mechanism of action
Colchicine exerts its effects through several distinct mechanisms depending on the target tissue:
- Microtubule Disruption: Binds irreversibly to tubulin → inhibits microtubule polymerization → interferes with sol-gel formation and the mitotic spindle → arrests cell division in metaphase.
- Antifibrotic Activity: Stimulates collagenase activity → increases the breakdown of collagen and decreases its formation, mitigating hepatic fibrosis.
- Anti-Amyloid Effect: Blocks the synthesis and secretion of Serum Amyloid A (SAA) (an acute-phase reactant protein) by hepatocytes → prevents the formation of amyloid-enhancing factor → halts amyloid deposition in tissues.
- Anti-inflammatory (Gout): Inhibits neutrophil motility and phagocytosis of monosodium urate crystals → reduces the release of inflammatory mediators.
Safety & warnings
Contraindications
- Serious renal dysfunction
- Serious gastrointestinal dysfunction
- Serious cardiac dysfunction
- Pregnancy (unless benefits strictly outweigh risks)
- Severe renal impairment
Adverse effects
- Nausea
- Vomiting
- Diarrhea
- Abdominal pain
- Anorexia
- Bone marrow suppression (with prolonged use)
- Neutropenia (rare)
- Severe local irritation/thrombophlebitis (if extravasated IV)
- Diarrhoea
- Renal damage (rare)
- Bone marrow suppression (rare)
- Myopathy (rare)
- Peripheral neuropathy (rare)
- Increased serum ALP
- Decreased platelet counts
Precautions
Contraindications & Warnings
- Absolute Contraindications: Patients with serious renal, gastrointestinal, or cardiac dysfunction.
- Caution: Use with extreme care in geriatric or debilitated patients, and those in the early stages of organ dysfunction.
- Reproductive Safety: Colchicine is teratogenic (FDA Category C for oral, Category D for parenteral) and reduces spermatogenesis. Use during pregnancy only if the potential benefits strictly outweigh the risks. Use cautiously in nursing mothers.
- Veterinary Status: Use is considered somewhat controversial and experimental, as safety and efficacy are not definitively documented in all target species.
Drug interactions
May cause additive myelosuppression when used concurrently with colchicine.
Possible increased risk of nephrotoxicity and myotoxicity
May increase the risks of thrombocytopenia, leucopenia, or bone marrow depression
May cause additive myelosuppressive effects
Monitoring
- Clinical efficacy
- Adverse effects (especially GI signs as early indicators of toxicity)
- CBC (to monitor for bone marrow suppression)
- Gastrointestinal signs (vomiting, diarrhea)
- Complete Blood Count (platelets, WBCs)
- Liver enzymes (ALP)
- Renal function parameters
- Urinalysis
Pharmacokinetics
Half-life
Absorption
Absorbed from the GI tract with a significant first-pass effect.
Distribution
Distributed into several tissues, but highly concentrated in leukocytes.
Metabolism
Metabolized in the liver (deacetylated) and other tissues. Undergoes extensive enterohepatic recycling (biliary secretion and GI reabsorption), which contributes to its intestinal toxicity.
Elimination
Primarily excreted in feces (as unchanged drug and metabolites), with some renal excretion. Patients with severe renal disease may have prolonged half-lives.
Overdose
Toxicity Profile
Colchicine has a narrow therapeutic index and can be highly toxic even after relatively small overdoses. In humans, ingestion of as little as 7 mg has been fatal, with 65 mg considered a lethal dose in adults.
Clinical Signs of Overdose
- Early Signs: Severe gastrointestinal distress (anorexia, vomiting, bloody diarrhea, paralytic ileus).
- Advanced Signs: Renal failure, hepatotoxicity, pancytopenia, ascending paralysis, shock, and vascular collapse.
Management
- No specific antidote exists.
- Decontamination: Gut removal techniques should be employed when applicable. Due to extensive enterohepatic recycling, administering repeated doses of activated charcoal along with a saline cathartic is highly recommended to interrupt systemic reabsorption.
- Supportive Care: Aggressive fluid therapy, symptomatic management, and potentially peritoneal dialysis.
Available products
Formulations
- Oral tablets
- Injection (human-labeled)
- 0.5 mg tablets
Human-labeled
- Colchicine Oral Tablets: 0.6 mg (1/100 gr) (Colcrys, generic)
- 0.5 mg tablets
Regulatory status
POM (Prescription Only Medicine). Used off-label under the cascade.
POM (Prescription Only Medicine). Used off-label under the cascade.
No regulatory data for: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store tablets in tight, light-resistant containers. Injection should be diluted only in 0.9% sodium chloride or sterile water for injection. Do not use D5W or bacteriostatic sodium chloride as precipitation may occur. Discard turbid solutions.
Client information
Important Information for Pet Owners
Colchicine is a specialized medication used to treat specific liver conditions or genetic fever syndromes (such as in Shar-Peis). Because it is a potent drug, careful monitoring is essential.
- Watch for Stomach Upset: The most common and earliest signs of a problem are nausea, vomiting, diarrhea, or loss of appetite. If you notice any of these, stop the medication and contact your veterinarian immediately.
- Investigational Use: This drug is often used 'off-label' in veterinary medicine, meaning it is prescribed based on clinical experience rather than formal veterinary approval.
- Safety Precautions:
- Keep this medication strictly out of reach of children and other pets. Even a small accidental dose can be highly dangerous.
- Pregnant women should avoid handling the medication or coming into contact with the treated pet's urine. If you must handle it, wear gloves.
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.