Fosnetupitant 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
Fosnetupitant
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.
Fosnetupitant is a medicine used to help prevent nausea from chemotherapy. Once in the body, it turns into netupitant, which can slow down a liver enzyme (called CYP3A4) that normally helps break down colchicine, your gout or FMF medicine.
When that enzyme is blocked, colchicine can build up to higher levels than usual. That matters because too much colchicine can be very serious, even life-threatening. The good news is this is very manageable. Your care team can lower your colchicine dose or space out your doses, and keep an eye on you. Please talk with your pharmacist or doctor before changing anything on your own.
Effect: Netupitant (the active moiety of fosnetupitant) inhibits CYP3A4, reducing metabolism of the CYP3A4 substrate colchicine and increasing colchicine exposure, with risk of fatal toxicity.
- Direction: Increased colchicine AUC/Cmax (enzyme inhibition; colchicine is not a prodrug).
- Evidence: Theoretical, extrapolated from netupitant effects on erythromycin and dexamethasone (dexamethasone AUC increase persisted up to 8 days).
- Onset: Unspecified; inhibition may persist ~1 to 2 weeks.
Management: Avoid coadministration within 1 week. If required, reduce colchicine daily dose or frequency per indication-specific limits, monitor for colchicine toxicity, and discontinue immediately if suspected. Avoid entirely in renal or hepatic impairment.
What happens
Increased colchicine exposure and an increased risk of fatal toxicity
Interaction Deep Dive
In a pharmacokinetic investigation, giving netupitant together with erythromycin, a CYP3A4 substrate, raised the mean AUC and Cmax of erythromycin. When netupitant was administered as a single dose, elevations in the AUC of dexamethasone (a CYP3A4 probe substrate) persisted for as long as 8 days. The combination of colchicine, which is a CYP3A4 substrate, with a CYP3A4 inhibitor like netupitant should be avoided for a period of 1 week. Should a CYP3A4 substrate need to be given within 1 week of netupitant 4, or if using the two together cannot be avoided, modify the colchicine dose by lowering either the daily amount or how often it is taken 3. When concurrent use, or use within 14 days, is necessary, the colchicine regimen for a gout flare should be reduced from the standard 1.2 mg (2 tablets) followed one hour later by 0.6 mg (1 tablets) down to a single 1.2 mg (2 tablets) dose, and any repeat dose should not be given sooner than 3 days. For gout flare prophylaxis, decrease the colchicine dose from 0.6 mg twice daily to 0.6 mg daily, or from 0.6 mg once daily to 0.3 mg once daily. For patients who have familial Mediterranean fever and need colchicine along with a moderate CYP3A4 inhibitor, the colchicine total per day should not exceed 1.2 mg (which may be split as 0.6 mg twice daily). Watch for indications of colchicine toxicity, and stop colchicine right away if it is suspected 2. In addition, the concurrent use of colchicine with moderate CYP3A4 inhibitors should be avoided in patients who have renal or hepatic impairment 1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated colchicine metabolism by netupitant
How to manage this interaction
Keep taking both medicines exactly as prescribed and do not stop or change doses yourself. Here is what your care team typically does with this combination:
- Timing: They may avoid using colchicine within about a week of fosnetupitant when possible.
- Dose: If both are needed, your colchicine dose may be reduced or spaced out, individualized to your situation (gout flare, gout prevention, or familial Mediterranean fever).
- Monitoring: Your team may watch you more closely for colchicine toxicity.
Call your doctor right away if you notice muscle weakness or pain, numbness, severe diarrhea, vomiting, or unusual tiredness. Tell your pharmacist about any kidney or liver problems.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Fosnetupitant and Colchicine together?
Fosnetupitant can raise colchicine levels and increase the risk of serious toxicity, so your care team may lower or space out your colchicine and watch you closely. Keep taking both as prescribed and check with your pharmacist or doctor. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Fosnetupitant 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 Fosnetupitant and Colchicine interaction managed?
Keep taking both medicines exactly as prescribed and do not stop or change doses yourself. Here is what your care team typically does with this combination: Timing: They may avoid using colchicine within about a week of fosnetupitant when possible. Dose: If both are needed, your colchicine dose may be reduced or spaced out, individualized to your situation (gout flare, gout prevention, or familial… 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 Fosnetupitant 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 (4)
- 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: AKYNZEO(R) oral capsules, netupitant palonosetron oral capsules. Helsinn Therapeutics (US), Inc (per FDA), Iselin, NJ, 2018. DailyMed
Keep reading about Fosnetupitant
Keep reading about Colchicine
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