Colchicine and Taurursodiol: 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
Colchicine
Taurursodiol
No brand names on record
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. Colchicine (like Colcrys or Mitigare) leaves your body partly with the help of a little cellular "pump" called P-gp. Taurursodiol can slow that pump down. When the pump slows, more colchicine can build up in your body than usual, and that can raise the chance of colchicine side effects like nausea, diarrhea, stomach pain, or muscle aches.
I want to be honest with you: this concern is based on how these drugs work in theory, not on strong studies. Even so, colchicine is a drug where small changes matter, so please don't stop or change either medicine on your own. Let your pharmacist or doctor know you take both, and they can manage this safely.
Mechanism: Taurursodiol (with sodium phenylbutyrate) inhibits P-glycoprotein (P-gp). Colchicine is a P-gp substrate, so co-administration may reduce colchicine efflux and increase its systemic exposure (AUC/Cmax).
Direction: Increased colchicine exposure, raising risk of dose-related toxicity (GI effects, myotoxicity, myelosuppression). Neither agent is a prodrug here, so effect follows standard inhibitor logic.
- Evidence: Theoretical.
- Onset: Unspecified.
- Severity: Major, given colchicine's narrow margin.
- Management: Avoid where feasible; otherwise individualize colchicine dosing and monitor for toxicity, especially in renal/hepatic impairment or with other P-gp/CYP3A4 inhibitors.
What happens
Increased exposure of the P-gp substrate
Interaction Deep Dive
When sodium phenylbutyrate/taurursodiol, which inhibits P-gp, is taken together with a P-gp substrate, exposure to that substrate may rise. Such combinations should be avoided for P-gp substrates in which even a minor shift in plasma concentration could cause serious toxicities or diminished efficacy1.
Why it happens (mechanism)
Inhibition of P-gp substrate transport by sodium phenylbutyrate/taurursodiol
How to manage this interaction
The good news: your care team can manage this. Keep taking both medications exactly as prescribed unless your prescriber tells you otherwise.
- Tell your pharmacist and doctor that you take colchicine and taurursodiol together.
- Your team may choose to avoid the combination, adjust and individualize your colchicine dose, or watch you more closely for side effects.
- Report symptoms like ongoing nausea, diarrhea, stomach pain, unusual muscle weakness or pain, or unusual tiredness.
- Mention any kidney or liver problems, since these can add to the risk.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Colchicine and Taurursodiol together?
Taurursodiol may raise colchicine levels by slowing the P-gp pump that clears it, which can increase colchicine side effects. Don't change anything on your own; tell your pharmacist or doctor you take both so they can adjust and monitor. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Colchicine and Taurursodiol 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 Colchicine and Taurursodiol interaction managed?
The good news: your care team can manage this. Keep taking both medications exactly as prescribed unless your prescriber tells you otherwise. Tell your pharmacist and doctor that you take colchicine and taurursodiol together. Your team may choose to avoid the combination, adjust and individualize your colchicine dose, or watch you more closely for side effects. Report symptoms like ongoing nausea,… 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 Colchicine or Taurursodiol 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: RELYVRIO(TM) oral powder for suspension, sodium phenylbutyrate taurursodiol oral powder for suspension. Amylyx Pharmaceuticals Inc (per FDA), Cambridge, MA, 2022.
Keep reading about Colchicine
Keep reading about Taurursodiol
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