Rilzabrutinib 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
Rilzabrutinib
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.
Here's what's going on. Rilzabrutinib (Wayrilz) can slow down a natural "pump" in your body called P-gp. Colchicine leans on that pump to get moved out of your cells. When the pump is blocked, more colchicine can build up in your body than usual.
Colchicine has a narrow safety window, so even a small increase can matter. That can mean more stomach upset, diarrhea, nausea, or muscle aches. The good news is this is a predicted (theoretical) concern, and your care team can manage it easily by keeping a closer eye on you and adjusting your colchicine dose if needed. Please don't stop either medicine on your own, just talk with your pharmacist or doctor.
Mechanism: Rilzabrutinib inhibits P-glycoprotein (P-gp)-mediated efflux. Colchicine is a P-gp substrate with a narrow therapeutic index (NTI), so reduced efflux may increase colchicine exposure (AUC/Cmax) and the risk of dose-related toxicity.
- Direction: increased colchicine effect/exposure (neither drug is a prodrug here).
- Severity: moderate. Onset: unspecified. Evidence: theoretical.
- Toxicity watch: GI symptoms (nausea, vomiting, diarrhea), myopathy, myelosuppression, and in severe accumulation neuromuscular effects.
Management: Monitor more frequently for colchicine adverse reactions; the colchicine dose may need to be individualized and reduced by the care team, with heightened caution in renal or hepatic impairment.
What happens
Increased P-gp substrate with NTI exposure and an increased risk of P-gp substrate with NTI-related adverse reactions
Interaction Deep Dive
When rilzabrutinib, which inhibits P-gp, is given together with P-gp substrates that have a narrow therapeutic index (NTI), the exposure to the NTI P-gp substrate may rise, potentially heightening the likelihood of adverse reactions associated with these substrates. More frequent monitoring for adverse reactions of the P-gp substrate being used concurrently is advised1.
Why it happens (mechanism)
Inhibition of P-gp-mediated efflux transport of rilzabrutinib
How to manage this interaction
The takeaway: keep taking both medicines exactly as prescribed unless your care team tells you otherwise. This is a predicted interaction, and it is manageable.
- Your team may monitor you more closely for colchicine side effects while you are on both drugs.
- Your colchicine dose may need to be adjusted and individualized by your prescriber.
- Report new or worsening diarrhea, nausea, vomiting, muscle pain or weakness, numbness, or unusual tiredness promptly.
- Make sure your pharmacist has your full medication list and knows about any kidney or liver problems.
Check in with your pharmacist or prescriber before changing anything.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Rilzabrutinib and Colchicine together?
Rilzabrutinib can raise colchicine levels by blocking the P-gp pump, so watch for colchicine side effects like GI upset and muscle pain; your care team can manage this by monitoring you and adjusting your colchicine dose if needed. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Rilzabrutinib and Colchicine interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Rilzabrutinib and Colchicine interaction managed?
The takeaway: keep taking both medicines exactly as prescribed unless your care team tells you otherwise. This is a predicted interaction, and it is manageable. Your team may monitor you more closely for colchicine side effects while you are on both drugs. Your colchicine dose may need to be adjusted and individualized by your prescriber. Report new or worsening diarrhea, nausea, vomiting, muscle… 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 Rilzabrutinib 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 anything you'd monitor while I'm on both?
References (1)
- Product Information: WAYRILZ™ oral tablets, rilzabrutinib oral tablets. Genzyme Corporation (per FDA), Cambridge, MA, 2025. DailyMed
Keep reading about Rilzabrutinib
Keep reading about Colchicine
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