Colchicine and Nelfinavir: 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
Nelfinavir
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.
Let's talk about taking nelfinavir (an HIV medicine) together with colchicine (used for gout or familial Mediterranean fever). Your body clears colchicine using a liver enzyme called CYP3A4. Nelfinavir strongly blocks that enzyme, so colchicine can build up to dangerous levels in your blood.
This matters a lot. Too much colchicine can cause severe, even life-threatening, poisoning, with symptoms like bad diarrhea, vomiting, muscle weakness, and problems with your blood cells. Because of this, the combination is generally not recommended, and it's flat-out off-limits if you also have kidney or liver problems. Please don't stop or change either drug on your own. Talk with your doctor or pharmacist, who can adjust things safely.
Effect: Nelfinavir, a strong CYP3A4 inhibitor (and P-gp inhibitor), reduces colchicine metabolism and elimination, increasing colchicine exposure and the risk of life-threatening or fatal toxicity. Colchicine is the affected substrate (not a prodrug).
- Direction: increased colchicine AUC/Cmax, enhanced toxicity.
- Evidence: probable; fatal cases reported at therapeutic colchicine doses.
- Contraindicated in renal or hepatic impairment.
- Management (normal renal/hepatic function): reduce colchicine dose. Gout flare: 0.6 mg once, then 0.3 mg 1 hour later, no repeat course sooner than 3 days. Prophylaxis: 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 toxicity.
What happens
Increased colchicine exposure and an increased risk of fatal toxicity
Interaction Deep Dive
Pairing colchicine with strong CYP3A4 inhibitors is contraindicated, since colchicine toxicity that is life-threatening and fatal has been documented in such patients even when colchicine is used at therapeutic doses1. In individuals with renal or hepatic impairment, simultaneous use of colchicine and strong CYP3A4 inhibitors, which encompass every protease inhibitor apart from fosamprenavir, is contraindicated. For patients whose renal and hepatic function is normal and who are taking a strong CYP3A4 inhibitor concurrently or have taken one during the preceding 14 days, the colchicine dose must be modified. When treating a gout flare, lower the colchicine dose to a single 0.6 mg tablet followed one hour later by 0.3 mg, and do not repeat this dose sooner than 3 days. For gout flare prophylaxis, decrease colchicine from an initial 0.6 mg twice-daily regimen to 0.3 mg once daily, or from an initial 0.6 mg once-daily regimen to 0.3 mg every other day. In the management of familial Mediterranean fever, the daily colchicine dose should not exceed 0.6 mg (which may be administered as 0.3 mg twice daily)2. When colchicine must be given together with CYP3A4 inhibitors that additionally inhibit P-gp4, modify the colchicine dose by lowering either the daily amount 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
Both drugs are important, so the key is doing this safely with your care team, not stopping anything yourself.
- Tell your prescriber and pharmacist you take both, and mention any kidney or liver problems. This combination is not used in people with kidney or liver impairment.
- In people with normal kidney and liver function, the colchicine dose is lowered and spaced out (the exact reduced dose depends on whether it's for a gout flare, gout prevention, or familial Mediterranean fever), and this can be individualized by your team.
- Watch for toxicity signs: severe diarrhea, vomiting, muscle weakness or pain, numbness. Get medical help right away if these occur.
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 investigated, an interaction between colchicine and clarithromycin, a potent CYP3A4 inhibitor, led to fatal colchicine toxicity. Colchicine Cmax and AUC rose by 227.2% and 281.5%, respectively, after a single 0.6 mg colchicine dose was given to patients (n=23) who were receiving clarithromycin 250 mg twice daily for 7 days 21.
b) In a pharmacokinetic study, giving a single dose of colchicine to patients who received ritonavir 100 mg twice daily for 5 days (n=18) produced a 184.4% and 296% increase in colchicine Cmax and AUC compared with baseline levels, respectively 51.
Common questions
Can I take Colchicine and Nelfinavir together?
Nelfinavir can push colchicine to dangerous, potentially fatal levels, so this combination is contraindicated (especially with kidney or liver problems); if used at all, colchicine must be dose-reduced and closely monitored by your care team. Do not stop or change either drug on your own. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Colchicine and Nelfinavir 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 Nelfinavir interaction managed?
Both drugs are important, so the key is doing this safely with your care team, not stopping anything yourself. Tell your prescriber and pharmacist you take both, and mention any kidney or liver problems. This combination is not used in people with kidney or liver impairment. In people with normal kidney and liver function, the colchicine dose is lowered and spaced out (the exact reduced dose depen… 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 Nelfinavir 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 Nelfinavir
Keep reading about Colchicine
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