Belumosudil and Omaveloxolone: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 15, 2026 · Source data updated Jul 11, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Omaveloxolone
Belumosudil
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.
You've been prescribed two medicines, Skyclarys (omaveloxolone) and Rezurock (belumosudil). Skyclarys can speed up the way your body breaks down certain drugs, and belumosudil is one of those drugs. Because of this, your body may clear belumosudil a bit faster, which could make it less effective at doing its job.
Here's the reassuring part: this is based mostly on how these drugs are expected to behave, not strong real-world proof. Your care team can handle it by watching how well your belumosudil is working and adjusting your plan if needed. Please don't stop or change either medicine on your own, just bring this up with your pharmacist or doctor.
Effect: Omaveloxolone is a weak CYP3A4 inducer. Belumosudil is a CYP3A4 substrate, so co-administration may lower belumosudil exposure (AUC/Cmax) and potentially reduce its efficacy.
Direction: Induction, so reduced substrate effect (neither drug's active form is enhanced).
- Magnitude: Not established for belumosudil; in a probe study omaveloxolone reduced midazolam AUC by ~45%.
- Onset: Unspecified.
- Evidence: Theoretical / extrapolated from probe substrate data.
- Management: Monitor for loss of belumosudil efficacy (chronic GVHD control). Dose may need individualization by the care team; consider closer clinical follow-up.
What happens
Reduced CYP3A4 substrate exposure and reduced efficacy of CYP3A4 substrate
Interaction Deep Dive
When omaveloxolone (a weak inducer of CYP3A4) is taken together with CYP3A4 substrates, the exposure to those substrates can decline, potentially diminishing their effectiveness. Watch for reduced efficacy of the co-administered agent whenever a CYP3A4 substrate is given alongside omaveloxolone. A drug interaction study demonstrated that coadministering omaveloxolone with midazolam lowered the AUC of midazolam (a CYP3A4 substrate) by roughly 45%1.
Why it happens (mechanism)
Induction of CYP3A4 substrate metabolism by omaveloxolone
How to manage this interaction
Keep taking both medicines exactly as prescribed unless your care team tells you otherwise. The main step here is watching to make sure your belumosudil (Rezurock) keeps working well.
- Your team may monitor you more closely for any signs that your belumosudil is not controlling your condition as expected.
- Your dose may need to be adjusted and individualized by your care team based on how you respond.
- Report any worsening or return of your symptoms to your pharmacist or prescriber.
Don't stop or adjust either drug on your own. Ask your pharmacist or doctor if you have questions.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) In a drug interaction study, coadministration of omaveloxolone with midazolam reduced the AUC of midazolam (a CYP3A4 substrate) by roughly 45% 1.
Common questions
Can I take Belumosudil and Omaveloxolone together?
Skyclarys may make belumosudil work a little less effectively by speeding up its breakdown, so your care team may monitor you more closely and adjust the dose if needed. Keep taking both as prescribed and report any worsening symptoms. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Belumosudil and Omaveloxolone interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Belumosudil and Omaveloxolone interaction managed?
Keep taking both medicines exactly as prescribed unless your care team tells you otherwise. The main step here is watching to make sure your belumosudil (Rezurock) keeps working well. Your team may monitor you more closely for any signs that your belumosudil is not controlling your condition as expected. Your dose may need to be adjusted and individualized by your care team based on how you respon… 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 Belumosudil or Omaveloxolone 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 (1)
- Product Information: Skyclarys® oral capsules, omaveloxolone oral capsules. Biogen U.S. Corporation, Cambridge, MA, 2026. DailyMed
Keep reading about Omaveloxolone
Keep reading about Belumosudil
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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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