Fexinidazole and Colchicine: 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
Fexinidazole
No brand names on recordColchicine
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.
Here's what's going on. Fexinidazole can slow down a liver enzyme (called CYP3A4) that your body uses to break down colchicine. When that clean-up slows, colchicine can build up to higher levels than intended. Colchicine has a narrow safety window, so even a modest rise matters. Higher levels can mean more side effects like stomach upset, diarrhea, nausea, muscle aches, or weakness.
The good news: this is a known, manageable concern. Please don't stop or change either medicine on your own. Talk with your pharmacist or doctor, they can decide the safest plan for you, including whether these two should be taken together.
Mechanism: Fexinidazole inhibits CYP3A4, reducing metabolism of the CYP3A4 substrate colchicine and increasing its systemic exposure (AUC/Cmax). Colchicine is not a prodrug, so inhibition raises active drug levels and toxicity risk.
- Direction: increased colchicine exposure and adverse-effect risk (GI toxicity, myopathy, neuromyopathy, and in severe cases myelosuppression).
- Severity: major; onset: unspecified; evidence: theoretical.
- NTI consideration: colchicine has a narrow margin, so small PK changes are clinically relevant.
- Management: avoid concomitant use per labeling; if unavoidable, dose reduction and closer clinical monitoring individualized by the care team.
What happens
An increased CYP3A4 substrate exposure
Interaction Deep Dive
Because fexinidazole acts as a CYP3A4 inhibitor, combining it with CYP3A4 substrates should be avoided; elevated levels of the substrate drugs raise the likelihood of adverse reactions1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism by fexinidazole
How to manage this interaction
What your care team may do:
- Consider avoiding the combination, since the guidance on file is to avoid using fexinidazole with colchicine.
- If both are truly needed, your colchicine dose may need to be adjusted and individualized by your care team.
- They may monitor you more closely for colchicine side effects such as diarrhea, nausea, muscle pain, or weakness.
What you should do: keep taking both exactly as prescribed for now, and don't stop or change anything on your own. Ask your pharmacist or prescriber whether these two medicines should be taken together, and report new symptoms promptly.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Fexinidazole and Colchicine together?
Fexinidazole can raise colchicine levels and its guidance is to avoid using them together; check with your pharmacist or doctor before combining them. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Fexinidazole and Colchicine interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Fexinidazole and Colchicine interaction managed?
What your care team may do: Consider avoiding the combination, since the guidance on file is to avoid using fexinidazole with colchicine. If both are truly needed, your colchicine dose may need to be adjusted and individualized by your care team. They may monitor you more closely for colchicine side effects such as diarrhea, nausea, muscle pain, or weakness. What you should do: keep taking both ex… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Fexinidazole or Colchicine 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 (1)
- Product Information: Fexinidazole oral tablets, fexinidazole oral tablets. sanofi-aventis US LLC (per FDA), Bridgewater, NJ, 2021. DailyMed
Keep reading about Fexinidazole
Keep reading about Colchicine
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