Colchicine and Ivacaftor: 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
Ivacaftor
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.
Here's what's going on. Colchicine is broken down and pushed out of your body by two systems in your gut and liver (an enzyme called CYP3A and a pump called P-gp). Ivacaftor (Kalydeco) can slow both of these down. When that happens, colchicine can build up higher than it should and stay around longer.
Colchicine has a narrow safety window, so even a little extra can cause more side effects like diarrhea, stomach upset, muscle pain, or weakness. The good news is this is very manageable. Don't change anything on your own. Just let your pharmacist or doctor know you take both, and they can watch you closely and adjust your dose if needed.
Mechanism: Ivacaftor inhibits P-gp-mediated efflux and CYP3A-mediated metabolism. Colchicine is a substrate of both, so coadministration may increase colchicine exposure (AUC/Cmax) and prolong its effect. Neither agent is a prodrug; the direction is increased colchicine effect and toxicity risk.
- Direction: increased colchicine exposure
- Severity: major; colchicine is narrow therapeutic index
- Onset: unspecified
- Evidence: theoretical
Management: Use caution. If coadministered, monitor for colchicine toxicity (GI symptoms, myopathy, myelosuppression). Dose may need to be reduced and individualized, especially with hepatic or renal impairment. Note: lumacaftor/ivacaftor differs (lumacaftor induces CYP3A).
What happens
Increased P-gp/CYP3A substrate exposure
Interaction Deep Dive
Exercise caution when ivacaftor or products that contain ivacaftor are given together with a P-gp/CYP3A substrate that has a narrow therapeutic index (such as everolimus and sirolimus), because the therapeutic effect and adverse reactions of the P-gp/CYP3A substrate may be heightened or extended. When such coadministration cannot be avoided, apply appropriate monitoring1. Furthermore, lumacaftor/ivacaftor should not be given alongside CYP3A substrates that have a narrow therapeutic index (such as everolimus and sirolimus), since lumacaftor is a strong inducer of CYP3A and may reduce the exposure and therapeutic effect of the CYP3A substrate2.
Why it happens (mechanism)
Inhibition of P-gp-mediated efflux transport by ivacaftor; inhibition of CYP3A-mediated metabolism by ivacaftor
How to manage this interaction
Keep taking both exactly as prescribed unless your care team tells you otherwise. This interaction can usually be managed with a few simple steps.
- Tell your pharmacist and prescriber that you take both ivacaftor and colchicine.
- Your team may monitor you more closely and, if needed, your colchicine dose may be adjusted and individualized.
- Watch for and report side effects of too much colchicine: ongoing diarrhea, nausea, vomiting, unusual muscle pain or weakness, numbness, or feeling unusually tired.
- Mention any kidney or liver problems, since these can raise the risk.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) Giving ivacaftor together with midazolam, a sensitive CYP3A substrate, raised midazolam exposure by 1.5-fold. Giving ivacaftor together with digoxin, a sensitive P-gp substrate, raised digoxin exposure by 1.3-fold 3.
Common questions
Can I take Colchicine and Ivacaftor together?
Ivacaftor can raise colchicine levels by slowing how it is broken down and cleared, so keep taking both as prescribed and ask your pharmacist or doctor to monitor you and adjust the dose if needed. Report any lasting stomach upset or muscle pain or weakness. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Colchicine and Ivacaftor 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 Ivacaftor interaction managed?
Keep taking both exactly as prescribed unless your care team tells you otherwise. This interaction can usually be managed with a few simple steps. Tell your pharmacist and prescriber that you take both ivacaftor and colchicine. Your team may monitor you more closely and, if needed, your colchicine dose may be adjusted and individualized. Watch for and report side effects of too much colchicine: on… 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 Ivacaftor 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 (3)
- Product Information: SYMDEKO(R) oral tablets, tezacaftor ivacaftor oral tablets and ivacaftor oral tablets. Vertex Pharmaceuticals Incorporated (per manufacturer), Boston, MA, 2020. DailyMed
- Product Information: ORKAMBI(R) oral tablets, lumacaftor ivacaftor oral tablets. Vertex Pharmaceuticals Incorporated (per manufacturer), Boston, MA, 2018. DailyMed
- Product Information: KALYDECO(R) oral tablets, oral granules, ivacaftor oral tablets, oral granules. Vertex Pharmaceuticals Incorporated (per FDA), Boston, MA, 2023. DailyMed
Keep reading about Ivacaftor
Keep reading about Colchicine
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