Colchicine and Mifepristone: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 2, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Mifepristone
Colchicine
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
Mifepristone can make colchicine build up in your body. Colchicine (used for gout or familial Mediterranean fever) is normally broken down by a liver enzyme called CYP3A4. Mifepristone slows that enzyme down, so colchicine can climb to dangerous levels. That matters a lot because colchicine has a narrow safety window, and too much can cause severe, even life-threatening problems like bad diarrhea, muscle weakness, and harm to your blood cells.
The good news is your care team knows how to handle this. Please do not start, stop, or change either medicine on your own. Talk with your pharmacist or doctor, who may lower your colchicine dose, space it out, or watch you more closely.
Mechanism: Mifepristone is a strong CYP3A4 inhibitor; colchicine is a CYP3A4 (and P-gp) substrate. Inhibition reduces colchicine metabolism, increasing colchicine exposure (AUC/Cmax) and the risk of fatal toxicity.
- Direction: increased colchicine effect/toxicity
- Severity: contraindicated; Evidence: probable
- Contraindicated in patients with renal or hepatic impairment.
Management (normal renal/hepatic function): Gout flare: 0.6 mg once, then 0.3 mg 1 hour later; do not repeat within 3 days. Gout prophylaxis: reduce 0.6 mg BID to 0.3 mg daily, or 0.6 mg daily to 0.3 mg every other day. FMF: max 0.6 mg/day. Monitor closely for colchicine toxicity (GI, myelosuppression, neuromyopathy).
What happens
Increased colchicine exposure and an increased risk of fatal toxicity
Interaction Deep Dive
Because therapeutic doses of colchicine have been associated with reports of life-threatening and fatal colchicine toxicity when taken alongside strong CYP3A4 inhibitors, this combination is contraindicated1. In patients with renal or hepatic impairment, giving colchicine together with strong CYP3A4 inhibitors, which includes every protease inhibitor other than fosamprenavir, is contraindicated. For patients whose renal and hepatic function is normal and who are taking a strong CYP3A4 inhibitor concurrently, or who have taken one within the previous 14 days, the colchicine dose must be modified. To treat a gout flare, lower the colchicine dose to a single 0.6 mg tablet, followed by 0.3 mg one hour afterward, and do not repeat this dose sooner than 3 days. For gout flare prophylaxis, decrease colchicine from an initial dose of 0.6 mg twice daily to 0.3 mg once daily, or from an initial dose of 0.6 mg once daily to 0.3 mg every other day. When treating familial Mediterranean fever, the colchicine dose should not exceed 0.6 mg per day (which may be administered as 0.3 mg twice daily)2. When colchicine must be given with CYP3A4 inhibitors that are also P-gp inhibitors4, modify the colchicine regimen by lowering either the daily dose or the frequency of dosing. Watch closely for signs of colchicine toxicity3.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism of colchicine
How to manage this interaction
This is a serious combination, but your care team can manage it. Keep taking both medicines exactly as prescribed unless your prescriber tells you otherwise.
- If you have kidney or liver problems, this combination is not recommended, so make sure your care team knows your full history.
- If your kidney and liver function are normal, your team may lower your colchicine dose or space out how often you take it, and this dose should be individualized by your care team.
- Your team may also monitor you more closely for signs of colchicine toxicity.
Call your pharmacist or doctor right away if you notice severe diarrhea, muscle weakness or pain, numbness, or unusual bruising or infections.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
2 reports — tap to read
a) While the interaction between colchicine and boceprevir has not been examined, an interaction between colchicine and clarithromycin, a potent CYP3A4 inhibitor, led to fatal colchicine toxicity. After a single 0.6 mg dose of colchicine was given to patients (n=23) who were receiving clarithromycin 250 mg twice daily for 7 days, colchicine Cmax and AUC rose by 227.2% and 281.5%, respectively 21.
b) In a pharmacokinetic study, giving a single dose of colchicine to patients who had received ritonavir 100 mg twice daily for 5 days (n=18) produced a 184.4% and 296% increase in colchicine Cmax and AUC, respectively, relative to baseline levels 51.
Common questions
Can I take Colchicine and Mifepristone together?
Mifepristone blocks the enzyme that clears colchicine, so colchicine can rise to dangerous levels. This combination is contraindicated in kidney or liver impairment, and otherwise your care team must lower or space out the colchicine dose and watch you closely. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Colchicine and Mifepristone interaction?
It is rated contraindicated. These should generally not be used together.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Colchicine and Mifepristone interaction managed?
This is a serious combination, but your care team can manage it. Keep taking both medicines exactly as prescribed unless your prescriber tells you otherwise. If you have kidney or liver problems, this combination is not recommended, so make sure your care team knows your full history. If your kidney and liver function are normal, your team may lower your colchicine dose or space out how often you… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Colchicine or Mifepristone need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (5)
- Product Information: LODOCO(R) oral tablets, colchicine oral tablets. AGEPHA Pharma USA, LLC (per FDA), Parsippany, NJ, 2023. DailyMed
- Product Information: COLCRYS oral tablets, colchicine oral tablets. Takeda Pharmaceuticals America Inc (per FDA), Deerfield, IL, 2020. DailyMed
- Product Information: GLOPERBA(R) oral solution, colchicine oral solution. Romeg Therapeutics LLC (per FDA), Woburn, MA, 2019. DailyMed
- Product Information: MITIGARE(R) oral capsules, colchicine oral capsules. Hikma Specialty USA Inc (per FDA), Columbus, OH, 2024. DailyMed
- Product Information: COLCRYS(TM) oral tablets, colchicine oral tablets. AR Scientific, Inc. Philadelphia, PA, 2009. DailyMed
Keep reading about Mifepristone
Keep reading about Colchicine
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