Quinine 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
Quinine
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's talk about taking quinine and colchicine together. Quinine can block a natural 'pump' in your body (called P-gp) that normally helps clear colchicine out. When that pump is slowed down, colchicine can build up to higher levels than intended.
That matters because colchicine, at high levels, can cause serious problems like severe stomach upset, diarrhea, muscle weakness, and effects on blood cells. This is why the combination is usually avoided. The good news is your care team knows how to handle this. If you have both of these prescribed, please check in with your pharmacist or doctor before your next dose so they can guide you safely.
Effect: Quinine (a P-gp inhibitor) may reduce P-gp-mediated efflux of colchicine, increasing colchicine exposure and risk of toxicity.
Direction/mechanism: Colchicine is a P-gp (and CYP3A4) substrate; inhibition of the efflux transporter raises colchicine plasma levels. Neither drug is a prodrug.
Evidence: Theoretical, but modeled on documented fatal toxicity with other P-gp inhibitors. Onset unspecified.
- Contraindicated with renal or hepatic impairment.
- In normal organ function, if unavoidable, reduce colchicine daily dose or dose frequency.
- Monitor closely for colchicine toxicity (GI symptoms, myopathy, cytopenias).
What happens
Increased colchicine exposure and an increased risk of colchicine toxicity
Interaction Deep Dive
Colchicine serves as a substrate for both CYP3A4 and P-gp. Reports of toxicity have surfaced when colchicine was given together with clarithromycin, an agent that inhibits both CYP3A4 and P-gp. Similar toxicities have been documented 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 reported in patients taking colchicine at therapeutic doses alongside P-gp inhibitors, such concurrent use is contraindicated 1. This combination is likewise contraindicated in individuals with renal or hepatic impairment, given that life-threatening and fatal drug interactions have been observed. For patients whose renal and hepatic function is normal 2, when coadministration of colchicine with a P-gp inhibitor cannot be avoided, adjust the colchicine dose by lowering either the daily amount or the frequency of dosing. 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
Because colchicine can build to dangerous levels when combined with a P-gp inhibitor like quinine, this combination is generally avoided, and it should not be used at all if you have kidney or liver problems.
What your care team may do:
- Consider whether an alternative is appropriate.
- If both are truly needed and your kidneys and liver work normally, the colchicine dose may need to be reduced or taken less often, individualized by your team.
- Watch you more closely for signs of colchicine toxicity.
What you should do: keep taking both exactly as prescribed for now, and promptly contact your pharmacist or prescriber. Report any severe diarrhea, vomiting, muscle weakness, numbness, or unusual fatigue right away.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Quinine and Colchicine together?
Quinine can raise colchicine to toxic levels by blocking its P-gp exit pump, so this pairing is usually avoided; contact your pharmacist or doctor before combining them and never use it if you have kidney or liver problems. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Quinine and Colchicine 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 Quinine and Colchicine interaction managed?
Because colchicine can build to dangerous levels when combined with a P-gp inhibitor like quinine, this combination is generally avoided, and it should not be used at all if you have kidney or liver problems. What your care team may do: Consider whether an alternative is appropriate. If both are truly needed and your kidneys and liver work normally, the colchicine dose may need to be reduced or ta… 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 Quinine 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 (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 Quinine
Keep reading about Colchicine
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