Glyburide and Belumosudil: 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
Belumosudil
Glyburide
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. Belumosudil (Rezurock) can slow down a transporter in your liver that normally helps move glyburide out of your blood. When that transporter is blocked, more glyburide can build up. Since glyburide is a diabetes pill that lowers blood sugar, higher levels could push your blood sugar too low.
Signs of low blood sugar include shakiness, sweating, dizziness, confusion, or feeling suddenly hungry. Please don't change either medicine on your own. The good news is your care team can manage this by adjusting your glyburide dose and watching your blood sugar more closely. Just let your doctor or pharmacist know you take both.
Mechanism: Belumosudil inhibits hepatic OATP1B1, reducing uptake/clearance of OATP1B1 substrates and increasing their systemic exposure. Glyburide is an OATP1B1 substrate, so coadministration may raise glyburide plasma concentrations and hypoglycemia risk.
- Direction: increased glyburide exposure (increased_drug_effect).
- Magnitude: not quantified for glyburide; index probe rosuvastatin showed Cmax up 3.6-fold and AUC up 4.6-fold.
- Evidence: probable. Onset: unspecified.
- Management: avoid combination with NTI OATP1B1 substrates; if unavoidable, reduce glyburide dose as needed and monitor fasting/postprandial glucose closely for hypoglycemia.
What happens
Increased OATP1B1 substrate exposure
Interaction Deep Dive
Concurrent use of belumosudil, which inhibits OATP1B1, together with an OATP1B1 substrate that has a narrow therapeutic index (NTI) should be avoided in situations where even small shifts in concentration could produce severe toxicity. When such combined use is unavoidable, reduce the dose of the OATP1B1 substrate as required. A drug interaction study demonstrated that adding belumosudil raised the Cmax and AUC of rosuvastatin (a substrate of both OATP1B1 and BCRP) by 3.6-fold and 4.6-fold, respectively1.
Why it happens (mechanism)
Inhibition of OATP1B1-mediated efflux transport by belumosudil
How to manage this interaction
What your care team may do:
- Where possible, avoid using these two together, or consider an alternative diabetes medicine.
- If you need both, your glyburide dose may need to be adjusted and individualized by your care team.
- Your team may monitor your blood sugar more closely while you're on both.
What you can do: Keep taking both exactly as prescribed unless told otherwise. Tell your pharmacist and prescriber you take both, check your blood sugar as directed, and report any low-blood-sugar symptoms (shakiness, sweating, dizziness, confusion) right away.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) In a drug interaction study, concurrent administration of belumosudil raised the Cmax and AUC of rosuvastatin (a substrate of OATP1B1 and BCRP) by 3.6-fold and 4.6-fold, respectively 1.
Common questions
Can I take Glyburide and Belumosudil together?
Belumosudil can raise glyburide levels and increase your risk of low blood sugar, so tell your care team you take both; they can adjust your dose and monitor your blood sugar closely. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Glyburide and Belumosudil 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 Glyburide and Belumosudil interaction managed?
What your care team may do: Where possible, avoid using these two together, or consider an alternative diabetes medicine. If you need both, your glyburide dose may need to be adjusted and individualized by your care team. Your team may monitor your blood sugar more closely while you're on both. What you can do: Keep taking both exactly as prescribed unless told otherwise. Tell your pharmacist and… 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.
Questions for your pharmacist
- Does my dose of Glyburide or Belumosudil 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: REZUROCK(R) oral tablets, belumosudil oral tablets. Kadmon Pharmaceuticals LLC (per FDA), Bridgewater, NJ, 2024. DailyMed
Keep reading about Belumosudil
Keep reading about Glyburide
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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