Seladelpar 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
Seladelpar
No brand names on record
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 belumosudil (Rezurock) along with seladelpar, so let's talk about how they work together. Belumosudil can block certain "transporter" proteins that normally help move seladelpar out of your body. When that happens, more seladelpar can build up in your bloodstream than usual.
That means the effects of seladelpar, including possible side effects, may be a bit stronger. This isn't a dangerous emergency, and it's something your care team handles all the time. Please keep taking both exactly as prescribed, and let your pharmacist or doctor know if you notice anything new so they can adjust your dose or check on you more closely if needed.
Effect: Increased seladelpar exposure when combined with belumosudil.
Mechanism: Belumosudil can inhibit OATP1B1 and BCRP, transporters involved in seladelpar disposition, reducing its efflux/clearance and raising systemic exposure. Neither agent is relevant here as a prodrug; seladelpar is the affected active drug, so exposure and pharmacodynamic effect increase.
Magnitude: In a dedicated study, cyclosporine (a dual OATP1B1/BCRP inhibitor) raised seladelpar AUC ~2.1-fold and Cmax ~2.9-fold; belumosudil is expected to act in the same direction, though exact magnitude is not defined.
- Onset: unspecified
- Evidence: probable
- Management: monitor closely for seladelpar adverse effects; dose may be individualized by the care team.
What happens
Increased seladelpar exposure
Interaction Deep Dive
Giving seladelpar together with agents that inhibit both BCRP and OATP1B1 may raise seladelpar levels. A drug interaction trial conducted in healthy volunteers found that administering a 10 mg dose of seladelpar alongside 600 mg cycloSPORINE (an inhibitor of both OATP1B1 and BCRP) raised seladelpar AUC 2.1-fold and Cmax 2.9-fold. Patients receiving this combination should be watched closely for adverse effects1.
Why it happens (mechanism)
Inhibition of OATP1B1-mediated efflux transport of seladelpar; inhibition of BCRP-mediated efflux transport of seladelpar
How to manage this interaction
Good news: this is a manageable combination. Here's what typically happens and what you can do.
- Keep taking both belumosudil and seladelpar as prescribed unless your doctor tells you otherwise.
- Your care team may monitor you more closely for seladelpar side effects since your levels may run higher.
- Your seladelpar dose may be adjusted and individualized by your prescriber based on how you respond.
- Report new symptoms (such as stomach upset, muscle aches, headache, or anything unusual) to your pharmacist or doctor.
Bring both medications up at your next visit so your team can plan the right monitoring for you.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) In a drug interaction study conducted in healthy subjects, giving a 10 mg dose of seladelpar together with 600 mg of cycloSPORINE (an inhibitor of OATP1B1 and BCRP) raised seladelpar AUC by 2.1-fold and Cmax by 2.9-fold, respectively 1.
Common questions
Can I take Seladelpar and Belumosudil together?
Belumosudil can raise seladelpar levels by blocking transporters that clear it, so your care team may watch you more closely for side effects and tailor your seladelpar dose. Keep taking both as prescribed and report anything new. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Seladelpar and Belumosudil 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 Seladelpar and Belumosudil interaction managed?
Good news: this is a manageable combination. Here's what typically happens and what you can do. Keep taking both belumosudil and seladelpar as prescribed unless your doctor tells you otherwise. Your care team may monitor you more closely for seladelpar side effects since your levels may run higher. Your seladelpar dose may be adjusted and individualized by your prescriber based on how you respond.… 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 Seladelpar 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 anything you'd monitor while I'm on both?
References (1)
- Product Information: LIVDELZI® oral capsules, seladelpar oral capsules. Gilead Sciences, Inc. (Per Manufacturer), Foster City, CA, 2026. DailyMed
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