Relacorilant 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
Relacorilant
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.
Here's what's going on with these two medicines. Relacorilant can slow down a liver enzyme called CYP3A4, which is the body's main way of breaking down many drugs. Belumosudil (Rezurock) is one of those drugs that the enzyme normally clears out.
When relacorilant slows that enzyme, belumosudil can build up higher in your body than intended. That means you could feel more of its side effects. The good news is this is very manageable. Your care team can watch you more closely, adjust doses, or choose a different option if needed. Please don't stop or change anything on your own. Just let your pharmacist or doctor know you take both so they can plan for it.
Effect: Relacorilant inhibits CYP3A4-mediated metabolism, increasing exposure (AUC/Cmax) of CYP3A4 substrates. Belumosudil is a CYP3A4 substrate, so co-administration is expected to raise belumosudil exposure and the risk of substrate-related adverse reactions.
- Mechanism: CYP3A4 inhibition by relacorilant (neither agent activated via this pathway).
- Direction: Increased belumosudil effect/toxicity.
- Severity/Evidence: Major; probable substantiation. Onset unspecified.
- Management: Avoid concomitant use unless otherwise recommended. If unavoidable, individualize dosing and increase clinical monitoring for belumosudil-related adverse effects.
What happens
Increased CYP3A4 substrate exposure and an increased risk of CYP3A4-substrate-related adverse reactions
Interaction Deep Dive
Unless specifically advised otherwise, do not use relacorilant together with CYP3A4 substrates. Taking them together may raise the exposure to these substrates and heighten the likelihood of adverse reactions associated with them1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism of relacorilant
How to manage this interaction
Both of these can be used safely with the right plan, but the labeling advises avoiding this combination unless your prescriber specifically recommends it, because relacorilant can raise belumosudil levels.
- Keep taking both exactly as prescribed. Do not stop or change doses on your own.
- Tell your pharmacist and doctor that you take both so they can decide whether to avoid the pairing, adjust and individualize your dose, monitor you more closely, or select an alternative.
- Report any new or stronger side effects promptly.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) In drug interaction studies, giving relacorilant at 350 mg in the fasted state (1.8 times the relacorilant exposure achieved at the recommended dosage) once daily for 10 days together with midazolam (a CYP3A4 substrate) raised Cmax by 3.1-fold and AUC by 8.9-fold 1.
Common questions
Can I take Relacorilant and Belumosudil together?
Relacorilant can raise belumosudil levels and side-effect risk by blocking CYP3A4, so this combination is generally avoided unless your care team specifically recommends and manages it. Keep taking both as prescribed and let your pharmacist or doctor know you use them together. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Relacorilant 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 Relacorilant and Belumosudil interaction managed?
Both of these can be used safely with the right plan, but the labeling advises avoiding this combination unless your prescriber specifically recommends it, because relacorilant can raise belumosudil levels. Keep taking both exactly as prescribed. Do not stop or change doses on your own. Tell your pharmacist and doctor that you take both so they can decide whether to avoid the pairing, adjust and i… 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 Relacorilant 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: LIFYORLI™ oral capsules, relacorilant oral capsules. Corcept Therapeutics Incorporated (Per Manufacturer), Redwood City, CA, 2026. DailyMed
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