Colchicine and Erythromycin: 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
Erythromycin
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.
Erythromycin can make colchicine build up in your body. Your body normally clears colchicine using a liver enzyme (CYP3A4) and a pump called P-gp. Erythromycin slows both of these down, so colchicine levels can climb higher than intended. That matters because colchicine is a medicine with a narrow safety window, and too much can cause serious problems like severe diarrhea, muscle weakness, blood cell changes, and in some cases life-threatening toxicity.
This combination is considered contraindicated, which is why it needs attention. Please don't stop either medicine on your own. Talk with your pharmacist or doctor. They can adjust your dose, use a different antibiotic, or watch you closely so you stay safe.
Mechanism: Colchicine is a substrate of CYP3A4 and P-gp. Erythromycin inhibits both, reducing colchicine metabolism and efflux, which increases colchicine exposure (AUC/Cmax) and toxicity risk. Neither drug is a prodrug; the effect is increased colchicine effect/toxicity.
- Severity: Contraindicated. Onset: delayed. Evidence: probable.
- NTI concern: colchicine has a narrow therapeutic index; fatal toxicities reported with dual inhibitors.
- Management: Contraindicated in renal or hepatic impairment. With normal function, reduce colchicine dose (gout flare: 1.2 mg once, repeat no sooner than 3 days; prophylaxis: 0.6 mg BID to 0.6 mg/day, or 0.6 mg/day to 0.3 mg/day; FMF max 1.2 mg/day).
- Monitor for GI, myotoxic, and myelosuppressive signs; discontinue if toxicity suspected.
What happens
Increased colchicine exposure and an increased risk of colchicine toxicity
Interaction Deep Dive
The combination of colchicine with P-gp inhibitors such as erythromycin is contraindicated1. Colchicine serves as a substrate for both CYP3A4 and P-gp. Coadministration with clarithromycin, which inhibits both CYP3A4 and P-gp, has been linked to fatal drug interactions and serious toxicities. In patients who have renal or hepatic impairment, giving colchicine together with a dual CYP3A4 and P-gp inhibitor is likewise contraindicated. When renal and hepatic function are normal, the colchicine dose must be modified3. For a gout flare, lower the colchicine dose to a single 1.2 mg dose, and delay any repeat dose until at least 3 days afterward. For gout flare prophylaxis, decrease colchicine from an initial regimen of 0.6 mg twice daily to 0.6 mg/day, or from an initial 0.6 mg/day to 0.3 mg/day. For patients with familial Mediterranean fever who need both colchicine and erythromycin, the colchicine dose should not exceed 1.2 mg daily (which may be administered as 0.6 mg twice daily)2. Compared with colchicine paired with a non-macrolide antibiotic, colchicine combined with a macrolide was linked to a significantly greater rate of heart failure and mortality4.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism of colchicine; inhibition of P-gp mediated efflux transport of colchicine
How to manage this interaction
This combination needs your care team's input because erythromycin can raise colchicine to dangerous levels. Keep taking both only as prescribed until you have spoken with them.
- Your team may avoid the combination and choose a different antibiotic when possible.
- If you have kidney or liver problems, this combination is generally not used together.
- If both are needed and your kidneys and liver work normally, your colchicine dose may need to be reduced and individualized, and your team may monitor you more closely.
- Call your pharmacist or doctor right away if you notice severe diarrhea, vomiting, muscle weakness, numbness, or unusual bruising or infections.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
2 reports — tap to read
a) In a retrospective cohort study (n=2199), the combination of colchicine with concurrent macrolide therapy (including erythromycin) was linked to a significantly greater rate of heart failure than colchicine with a non-macrolide antibiotic (n=12,670), at 18.3% versus 9.1%, respectively (OR, 1.06; 95% CI, 0.67 to 1.67). A significantly elevated mortality rate was likewise seen in the colchicine plus macrolide group relative to the colchicine plus non-macrolide antibiotic group (3.87% vs 2.28%; OR, 2.06; 95% CI, 1.07 to 3.97). No differences were found in the risk of rhabdomyolysis diagnosis, pancytopenia, muscle weakness, or acute hepatic failure 4.
b) In one case report, a patient on long-term colchicine therapy (1 mg daily) for familial Mediterranean fever and amyloidosis affecting the kidney, liver, and GI tract developed severe, life threatening colchicine toxicity after two weeks of erythromycin (2 g daily) treatment for bronchitis. A serum colchicine concentration of 22 nanograms/milliliter (ng/mL; 1 to 2.5 ng/mL would have been anticipated) confirmed the diagnosis of colchicine toxicity. The patient's concurrent hepatic and renal impairment may have contributed to the toxic effects 5.
Common questions
Can I take Colchicine and Erythromycin together?
Erythromycin can push colchicine to toxic levels, so this pairing is contraindicated; don't combine them without your prescriber or pharmacist adjusting the plan first. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Colchicine and Erythromycin interaction?
It is rated contraindicated. These should generally not be used together.
How quickly could this interaction happen?
The documented onset is "delayed". Effects tend to build up gradually over days to weeks.
How is the Colchicine and Erythromycin interaction managed?
This combination needs your care team's input because erythromycin can raise colchicine to dangerous levels. Keep taking both only as prescribed until you have spoken with them. Your team may avoid the combination and choose a different antibiotic when possible. If you have kidney or liver problems, this combination is generally not used together. If both are needed and your kidneys and liver work… 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.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Colchicine or Erythromycin 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
- Tan MS, Gomez-Lumbreras A, Villa-Zapata L, et al: Colchicine and macrolides: a cohort study of the risk of adverse outcomes associated with concomitant exposure. Rheumatol Int 2022; 42(12):2253-2259. PubMed
- Caraco Y, Putterman C, Rahamimov R, et al: Acute colchicine intoxication: possible role of erythomycin administration. J Rheumatol 1992; 19:494-496.
Keep reading about Erythromycin
Keep reading about Colchicine
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