Lapatinib 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
Lapatinib
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.
Taking these two together needs a close look from your care team. Lapatinib (Tykerb) can block a natural 'pump' in your body called P-glycoprotein that normally helps push colchicine out. When that pump is slowed, colchicine can build up to higher levels than expected.
Colchicine has a narrow safety window, so even a small buildup can cause serious problems like severe diarrhea, muscle weakness, or effects on your blood cells. This combination is actually labeled as one to avoid at usual doses. Please don't stop or change either medicine on your own. Talk with your pharmacist or doctor, they can adjust things safely and watch you closely.
Mechanism: Colchicine is a P-gp (and CYP3A4) substrate. Lapatinib inhibits P-gp, reducing colchicine efflux and increasing systemic colchicine exposure. Neither drug is a prodrug here, so the effect is increased colchicine levels and toxicity risk.
- Direction: Increased colchicine AUC/Cmax, higher toxicity risk.
- Severity: Contraindicated per labeling; life-threatening and fatal toxicity reported with P-gp inhibitors.
- Evidence: Theoretical for this specific pair, extrapolated from class effects.
- Management: Contraindicated in renal or hepatic impairment. In normal organ function, if unavoidable, reduce colchicine daily dose or frequency and monitor closely for GI, myopathic, and hematologic toxicity.
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 toxicities when given together with clarithromycin, an agent that inhibits both CYP3A4 and P-gp. Such toxicities have likewise 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 alongside P-gp inhibitors, this combination is contraindicated 1. It is also 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 must be given with a P-gp inhibitor, modify the colchicine dose by lowering either the total daily amount or the frequency of dosing. Close monitoring for colchicine toxicity is warranted 3.
Why it happens (mechanism)
Inhibition of P-gp-mediated colchicine efflux transport
How to manage this interaction
This combination is generally one to avoid. Colchicine is a narrow-margin drug, and lapatinib can push its levels up.
- Keep taking both exactly as prescribed until you speak with your care team, do not stop on your own.
- Your team may avoid this pairing, especially 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 reduced or given less often, individualized by your care team.
- Expect closer monitoring for colchicine toxicity.
Report severe diarrhea, vomiting, muscle pain or weakness, numbness, or unusual bruising to your pharmacist or doctor right away.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Lapatinib and Colchicine together?
Lapatinib can raise colchicine to toxic levels, and this pairing is flagged as contraindicated at usual doses. Do not change anything yourself; have your pharmacist or doctor review it, since they may avoid the combo or reduce and closely monitor your colchicine. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Lapatinib 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 Lapatinib and Colchicine interaction managed?
This combination is generally one to avoid. Colchicine is a narrow-margin drug, and lapatinib can push its levels up. Keep taking both exactly as prescribed until you speak with your care team, do not stop on your own. Your team may avoid this pairing, especially if you have kidney or liver problems. If both are truly needed and your kidney and liver function are normal, your colchicine dose may n… 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 Lapatinib 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 Lapatinib
Keep reading about Colchicine
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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