Colchicine: uses, dosing, side effects & brands

Colchicine is an alkaloid obtained from the plant colchicum autumnale .

The FDA classifies colchicine as an alkaloid. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.

The elimination half-life of colchicine is about 27 to 31 hours (the label gives mean elimination half-lives of 26.6 to 31.2 hours in young healthy volunteers on 0.6 mg twice daily) — that is how long the body takes to clear half of a dose. This is the elimination (terminal) half-life the label reports after multiple oral doses; a separate single-dose study in the same label gives an apparent elimination half-life of about 25 hours in young adults. Colchicine is not a prodrug, and it has no active metabolite that outlasts it — it is demethylated by CYP3A4 to 2-O- and 3-O-demethylcolchicine, but the label states plasma levels of these metabolites are minimal (less than 5% of parent drug). Because colchicine recirculates through bile and gut, the label notes secondary plasma peaks 3 to 36 hours after a dose. Older adults: in the same single-dose study, subjects aged 60 to 70 had an apparent elimination half-life of about 30 hours (SD ±10.8) versus about 25 hours in those aged 18 to 30, and an older published report found peak levels and AUC roughly twice as high in elderly women, likely from reduced kidney function. Kidney impairment: the label says the pharmacokinetics in mild and moderate renal impairment are not known; in a published report of patients with familial Mediterranean fever and end-stage renal disease on dialysis, clearance was 75% lower and the plasma elimination half-life was prolonged (18.8 hours versus 4.4 hours in FMF patients with normal renal function — note these baseline figures come from that separate study, not from the healthy-volunteer numbers above). Colchicine is not removed by hemodialysis. Liver impairment: published data show wide variability; in some people with mild to moderate cirrhosis, clearance is significantly reduced and plasma half-life prolonged, and no pharmacokinetic data exist for severe hepatic impairment (Child-Pugh C). This is a pharmacokinetic figure only — it is not a drug-test detection window and not dosing guidance. Half-life is not the same as how long a drug test can detect the drug, and it varies with age, kidney and liver function.

It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run colchicine against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.

We track 4 colchicine-containing products in the U.S.: Mitigare, Colcrys, Gloperba and Lodoco. They are the same active ingredient; they differ in form, manufacturer, price and FDA recall record.

Across the brands we track, colchicine is currently marketed as capsule, tablet and solution, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.

We do not currently list a generic-labelled colchicine product. That does not always mean none exists — it means none appears under a generic name in the FDA data we track. Ask your pharmacist.

The FDA's Enforcement database lists 1 recall record whose product description mentions colchicine. The most recent: Colchicine Capsules 0.6 mg (Dec 18, 2024). A recall applies to specific lots, not to the drug as a whole — check the record for the affected lot numbers.

Diarrhea, by a wide margin. In the trial behind the label for colchicine 0.6 mg tablets, gastrointestinal side effects occurred in 26% of patients on the recommended flare dose (1.8 mg over one hour) versus 20% on placebo, with diarrhea in 23% and throat pain in 3%. The dose matters enormously: on a non-recommended high dose of 4.8 mg over six hours, 77% had GI reactions, 19% had severe diarrhea, and 17% vomited — none of which happened on the recommended dose. In familial Mediterranean fever, GI effects such as cramping, nausea, diarrhea, abdominal pain, and vomiting hit up to 20% of patients, usually within 24 hours. Severe GI symptoms are a warning sign of more serious toxicity, not something to push through.

No — the colchicine tablet label has no FDA boxed warning. That is not the same as low risk. Its most serious content appears under Contraindications and Warnings and Precautions: fatal overdose (the label reports deaths after as little as 7 mg taken over four days, and 100% mortality among people who ingested more than 0.8 mg/kg), fatal drug interactions, blood disorders including aplastic anemia at normal doses, and muscle and nerve toxicity with rhabdomyolysis. There is no antidote and colchicine is not removed by dialysis. Keep it out of reach of children and go to an emergency room immediately if too much is taken.

The label's contraindication is specific: if you have kidney or liver impairment, you must not take colchicine together with a P-glycoprotein inhibitor or a strong CYP3A4 inhibitor — a category that includes every protease inhibitor except fosamprenavir. In those patients, life-threatening and fatal colchicine toxicity has been reported at ordinary therapeutic doses, not overdoses. If you have normal kidney and liver function and need one of these drugs anyway, colchicine still has to be dose-reduced or interrupted, not simply continued. Tell your prescriber and pharmacist about kidney or liver disease before any new prescription, including a short antibiotic course.

Colchicine is cleared by P-gp and CYP3A4, and blocking either raises its blood level. The label reports fatal colchicine toxicity specifically with clarithromycin (a strong CYP3A4 inhibitor) and with cyclosporine (a P-gp inhibitor). Other named strong CYP3A4 inhibitors requiring a dose cut include ketoconazole, itraconazole, ritonavir and other protease inhibitors, nefazodone, and telithromycin. Moderate inhibitors requiring a dose cut include diltiazem, verapamil, erythromycin, fluconazole, aprepitant — and grapefruit juice, which the Medication Guide says to avoid entirely. Ranolazine is another P-gp inhibitor. Statins, fibrates, gemfibrozil, and digoxin add a separate risk: myopathy and rhabdomyolysis, including a reported fatality.

Two that don't require an overdose. Blood dyscrasias — myelosuppression, leukopenia, granulocytopenia, thrombocytopenia, pancytopenia, and aplastic anemia — have been reported at therapeutic doses, which is why your prescriber may check blood counts. And neuromuscular toxicity with rhabdomyolysis has been reported with long-term therapeutic dosing; people with reduced kidney function and older adults are at higher risk even with normal liver and kidney tests, and taking a statin, a fibrate, gemfibrozil, or cyclosporine alongside it raises the risk further. Report muscle pain, tenderness, weakness, or numbness and tingling. Once colchicine is stopped, symptoms generally resolve within one week to several months.