Colchicine and Lasmiditan: 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
Lasmiditan
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.
These two medicines can be a risky combination. Lasmiditan (Reyvow) can block a protein in your body called P-gp that normally helps push colchicine out. When that pump is slowed, colchicine can build up to higher levels than intended. Colchicine already has a narrow safety window, so higher levels can cause serious harm, including severe stomach upset, muscle problems, and effects on blood cells.
The good news is that your care team can manage this. Do not stop or change either medicine on your own. Instead, let your pharmacist or doctor know you take both, and they can decide the safest plan for you.
Mechanism: Colchicine is a P-gp (and CYP3A4) substrate. Lasmiditan inhibits P-gp, reducing colchicine efflux and increasing systemic exposure, raising the risk of colchicine toxicity. Neither agent is activated by this pathway, so the effect is increased colchicine levels.
- Direction: Increased colchicine exposure (narrow therapeutic index).
- Severity/status: Labeled contraindicated with P-gp inhibitors; life-threatening/fatal toxicity reported.
- Evidence: Theoretical for this specific pair; onset unspecified.
- Management: Contraindicated in renal or hepatic impairment. In normal organ function, if required, reduce colchicine daily dose or frequency and monitor closely for toxicity (GI, 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 toxicity when given together with clarithromycin, which inhibits both CYP3A4 and P-gp. Similar toxicities have been observed 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 along with P-gp inhibitors, this combination is contraindicated 1. The combination is likewise contraindicated in individuals with renal or hepatic impairment, given that life-threatening and fatal drug interactions have been reported. For patients whose renal and hepatic function is normal 2, when colchicine and a P-gp inhibitor must be given together, adjust the colchicine dose by lowering either the daily amount or the frequency of dosing. Monitor closely for colchicine toxicity 3.
Why it happens (mechanism)
Inhibition of P-gp-mediated colchicine efflux transport
How to manage this interaction
Keep taking both medicines exactly as prescribed until you speak with your care team, but do reach out to them promptly because this pairing needs review.
- This combination is generally contraindicated, and especially so if you have any kidney or liver problems.
- If both must be used and your kidney and liver function are normal, your team may lower the colchicine daily dose or reduce how often you take it, and monitor you more closely for toxicity.
- Report severe diarrhea, nausea, muscle pain or weakness, numbness, or unusual bruising or infections right away.
- Ask your pharmacist whether an alternative to one of these drugs is appropriate for you.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Colchicine and Lasmiditan together?
Lasmiditan can raise colchicine levels by blocking its P-gp transport, and this combination is generally contraindicated; contact your pharmacist or doctor before using them together, especially if you have kidney or liver problems. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Colchicine and Lasmiditan 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 Lasmiditan interaction managed?
Keep taking both medicines exactly as prescribed until you speak with your care team, but do reach out to them promptly because this pairing needs review. This combination is generally contraindicated, and especially so if you have any kidney or liver problems. If both must be used and your kidney and liver function are normal, your team may lower the colchicine daily dose or reduce how often you… 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 Lasmiditan 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 Lasmiditan
Keep reading about Colchicine
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