Colchicine and Amprenavir: 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
Amprenavir
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.
Let me explain this one simply. Amprenavir is an HIV medicine that slows down a liver enzyme (called CYP3A4) that your body normally uses to break down colchicine. When that enzyme is blocked, colchicine can build up in your body to higher levels than intended.
That matters because colchicine has a narrow safety window. Too much can cause serious problems, and in some cases colchicine toxicity has been fatal. Watch for warning signs like severe diarrhea, vomiting, stomach pain, muscle weakness, or unusual tiredness. The good news: this is very manageable. Your care team can lower your colchicine dose and keep a closer eye on you. Please talk with your pharmacist or doctor before changing anything yourself.
Effect: Amprenavir inhibits CYP3A4, reducing colchicine metabolism and increasing colchicine exposure (higher plasma concentrations), with risk of potentially fatal colchicine toxicity. Colchicine is a narrow-therapeutic-index substrate; neither drug is a prodrug, so the direction is increased colchicine effect.
- Mechanism: CYP3A4 inhibition (amprenavir treated as a moderate inhibitor for dosing purposes; also P-gp relevant).
- Evidence: theoretical; severity: major; onset unspecified.
- Management: Reduce colchicine dose/frequency. Gout flare: 1.2 mg once, no repeat sooner than 3 days. Prophylaxis: reduce 0.6 mg BID to 0.6 mg daily, or 0.6 mg daily to 0.3 mg daily. FMF max 1.2 mg/day. Monitor for toxicity; avoid entirely in renal or hepatic impairment.
What happens
Increased colchicine exposure and an increased risk of fatal toxicity
Interaction Deep Dive
Taking colchicine together with a moderate CYP3A4 inhibitor should be avoided, since this combination can raise colchicine plasma levels and lead to fatal colchicine toxicity. When coadministration cannot be avoided, the colchicine dose must be modified by lowering either the total daily amount or how often it is taken3. For situations requiring concurrent use, or use within a 14 day window, the colchicine regimen for a gout flare should be changed from the standard 1.2 mg (2 tablets) followed one hour later by 0.6 mg (1 tablet) to a single dose of 1.2 mg (2 tablets), and any repeat dose must wait at least 3 days. For gout flare prophylaxis, a starting regimen of 0.6 mg twice daily should be cut to 0.6 mg daily, and a starting regimen of 0.6 mg once daily should be cut to 0.3 mg once daily. For patients who have familial Mediterranean fever and need to use colchicine alongside a moderate CYP3A4 inhibitor, the total daily colchicine dose should not exceed 1.2 mg (which may be administered as 0.6 mg twice daily). Watch for any signs and symptoms indicating colchicine toxicity, and stop colchicine right away if toxicity 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 metabolism of colchicine
How to manage this interaction
Do not stop either medicine on your own. Your care team can manage this safely, usually by lowering your colchicine dose or spacing it out further and watching you more closely.
- For a gout flare, they may reduce the total dose and delay any repeat dose by several days.
- For gout prevention, they may cut the daily dose.
- They will watch for colchicine toxicity (severe diarrhea, vomiting, muscle weakness, numbness), and would stop colchicine right away if it is suspected.
- This combination is generally avoided if you have kidney or liver problems.
Please tell your pharmacist or prescriber that you take both so they can tailor your dose.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
Common questions
Can I take Colchicine and Amprenavir together?
Amprenavir can raise colchicine levels and risk serious toxicity, so your care team will lower the colchicine dose and monitor you closely. Do not adjust anything on your own; check with your pharmacist or doctor. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Colchicine and Amprenavir 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 Amprenavir interaction managed?
Do not stop either medicine on your own. Your care team can manage this safely, usually by lowering your colchicine dose or spacing it out further and watching you more closely. For a gout flare, they may reduce the total dose and delay any repeat dose by several days. For gout prevention, they may cut the daily dose. They will watch for colchicine toxicity (severe diarrhea, vomiting, muscle weakn… 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 Amprenavir 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: 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
Keep reading about Amprenavir
Keep reading about Colchicine
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