Abemaciclib and Relacorilant: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 10, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Relacorilant
Abemaciclib
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.
These two medicines can interact. Relacorilant can block a liver enzyme called CYP3A4, which is the same enzyme your body uses to break down abemaciclib (Verzenio). When that clean-up slows down, abemaciclib can build up higher than intended in your body.
Higher levels can mean more side effects from abemaciclib, such as diarrhea, low blood counts, fatigue, or nausea. The good news is that your care team knows about this and can manage it, often by adjusting doses, watching you more closely, or choosing a different combination. Please don't change anything on your own. Talk with your pharmacist or oncologist first.
Interaction: Relacorilant is a CYP3A4 inhibitor; abemaciclib is a CYP3A4 substrate. Concomitant use is expected to reduce abemaciclib clearance, increasing its exposure (AUC/Cmax) and the risk of dose-related toxicity.
- Direction: Increased abemaciclib effect and toxicity (neutropenia, diarrhea, hepatotoxicity, ILD/pneumonitis, VTE).
- Mechanism: Inhibition of CYP3A4-mediated metabolism.
- Evidence: Probable. Onset: unspecified.
- Management: Avoid concomitant use unless otherwise recommended. If combined, consider abemaciclib dose reduction per labeling and enhanced monitoring (CBC, LFTs, GI/pulmonary symptoms).
What happens
Increased CYP3A4 substrate exposure and an increased risk of CYP3A4-substrate-related adverse reactions
Interaction Deep Dive
Do not use relacorilant together with CYP3A4 substrates unless there is a specific recommendation to do so. 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
What your care team may do:
- Avoid using these two together when possible, as recommended by the prescribing information.
- If both are truly needed, your abemaciclib dose may be adjusted and individualized by your team.
- Your team may monitor you more closely, watching blood counts, liver tests, and for side effects like diarrhea, fatigue, or breathing changes.
What you should do: Keep taking both exactly as prescribed unless told otherwise. Do not stop or change either drug on your own. Ask your pharmacist or oncologist to confirm this combination is right for you and report any new or worsening side effects.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) In studies of drug interactions, giving relacorilant 350 mg under fasted conditions (1.8 times the relacorilant exposure achieved at the recommended dosage) once daily for 10 days together with midazolam (a CYP3A4 substrate) raised the Cmax by 3.1-fold and the AUC by 8.9-fold 1.
Common questions
Can I take Abemaciclib and Relacorilant together?
Relacorilant can raise abemaciclib levels and side effects by slowing its breakdown, so this combination is generally avoided unless your care team specifically recommends it with dose adjustment and closer monitoring. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Abemaciclib and Relacorilant 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 Abemaciclib and Relacorilant interaction managed?
What your care team may do: Avoid using these two together when possible, as recommended by the prescribing information. If both are truly needed, your abemaciclib dose may be adjusted and individualized by your team. Your team may monitor you more closely, watching blood counts, liver tests, and for side effects like diarrhea, fatigue, or breathing changes. What you should do: Keep taking both ex… 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 Abemaciclib or Relacorilant 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
Keep reading about Relacorilant
Keep reading about Abemaciclib
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.
Check another combination
Our instant two-drug interaction checker is almost here.
Still have questions about this combination?
Every question gets a real answer from a licensed pharmacist — free, and usually within a day.
Ask the pharmacist