Colchicine and Asunaprevir: 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
Asunaprevir
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.
These two medicines can be a dangerous combination. Colchicine is normally cleared out of your body by a kind of "pump" called P-gp. Asunaprevir can block that pump, so colchicine builds up and stays in your body longer than it should. Even at a normal dose, too much colchicine can cause serious problems like severe diarrhea, muscle weakness, and dangerous effects on your blood and organs.
Please don't stop or change either medicine on your own. Let your pharmacist or doctor know you're taking both. This is something your care team can manage, often by adjusting your colchicine dose and watching you closely.
Interaction: Asunaprevir inhibits P-gp-mediated efflux of colchicine (a CYP3A4 and P-gp substrate), reducing colchicine clearance and increasing systemic exposure. Direction: increased colchicine effect/toxicity. Neither drug requires bioactivation here, so this is a straightforward exposure increase.
- Severity: Contraindicated; life-threatening/fatal colchicine toxicity reported with P-gp inhibitors.
- Evidence: Theoretical (extrapolated from clarithromycin and other P-gp/CYP3A4 inhibitor data).
- Management: Avoid, especially in renal or hepatic impairment. If unavoidable in patients with normal renal/hepatic function, reduce colchicine daily dose or dosing frequency and monitor closely for toxicity (GI symptoms, myopathy, myelosuppression).
What happens
Increased colchicine exposure and an increased risk of colchicine toxicity
Interaction Deep Dive
As a substrate of both CYP3A4 and P-gp, colchicine has been associated with reported toxicities when given together with clarithromycin, an agent that inhibits both CYP3A4 and P-gp. Such toxicities have likewise been seen when colchicine was combined with a CYP3A4 inhibitor and when it was combined with a P-gp inhibitor3. Because life-threatening and fatal colchicine toxicity has been documented in patients taking therapeutic doses of colchicine alongside P-gp inhibitors, this combination is contraindicated 1. The combination is similarly contraindicated in individuals with renal or hepatic impairment, since life-threatening and fatal drug interactions have been reported. For patients whose renal and hepatic function is normal 2, when colchicine must be given concurrently with a P-gp inhibitor, the colchicine dose should be adjusted, either by lowering the daily amount or by decreasing how often it is taken. Watch carefully for signs of colchicine toxicity 3.
Why it happens (mechanism)
Inhibition of P-gp-mediated colchicine efflux transport
How to manage this interaction
What your care team may do:
- Because this pairing can cause serious colchicine buildup, prescribers often avoid using them together, particularly if you have kidney or liver problems.
- If both are truly needed and your kidney and liver function are normal, your colchicine dose may need to be lowered or taken less often. This should be individualized by your care team.
- They may monitor you more closely for signs of colchicine toxicity.
What you should do: Keep taking both exactly as prescribed and don't adjust anything yourself. Tell your pharmacist or doctor you're on both, and report symptoms like severe diarrhea, vomiting, muscle pain or weakness, or unusual tiredness right away.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Colchicine and Asunaprevir together?
Combining colchicine with asunaprevir can push colchicine to toxic levels and is generally avoided; don't change anything yourself, but check with your pharmacist or doctor so they can adjust the dose or monitor you. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Colchicine and Asunaprevir 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 Asunaprevir interaction managed?
What your care team may do: Because this pairing can cause serious colchicine buildup, prescribers often avoid using them together, particularly if you have kidney or liver problems. If both are truly needed and your kidney and liver function are normal, your colchicine dose may need to be lowered or taken less often. This should be individualized by your care team. They may monitor you more close… 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 Asunaprevir 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 Colchicine
Keep reading about Asunaprevir
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