Ribociclib and Ibrexafungerp: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Ribociclib
Ibrexafungerp
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.
What happens
Increased ibrexafungerp exposure
Interaction Deep Dive
Concomitant use of ibrexafungerp and a strong CYP3A inhibitor has significantly increased ibrexafungerp exposure. Coadministration of ibrexafungerp and ketoconazole 400 mg once daily for 15 days (a strong CYP3A4 and P-gp inhibitor) increased the ibrexafungerp AUC by 5.8-fold and Cmax by 2.5-fold. If ibrexafungerp and a strong CYP3A inhibitor are coadministered, reduce the ibrexafungerp dosage to 150 mg approximately 12 hours apart (eg, in the morning and in the evening) for one day1.
Why it happens (mechanism)
Inhibition of CYP3A-mediated metabolism of ibrexafungerp
Literature reports
1 report — tap to read
a) Coadministration of ketoconazole 400 mg once daily for 15 days (strong CYP3A4 and P-gp inhibitor) with ibrexafungerp, increased the ibrexafungerp AUC by 5.8-fold and Cmax by 2.5-fold 1.
Common questions
Can I take Ribociclib and Ibrexafungerp together?
Increased ibrexafungerp exposure Always confirm with your pharmacist or prescriber before making any change.
How serious is the Ribociclib and Ibrexafungerp 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 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 Ribociclib or Ibrexafungerp 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: Brexafemme(R) oral tablets, ibrexafungerp oral tablets. Scynexis, Inc. (per manufacturer), Jersey City, NJ, 2021.
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Keep reading about Ibrexafungerp
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