Clindamycin Vaginal and Ribociclib: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Ribociclib
Clindamycin Vaginal
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 exposure of CYP3A4 substrate and an increased risk of CYP3A4 substrate-related adverse reactions
Interaction Deep Dive
Concomitant use with ribociclib (a strong CYP3A4 inhibitor) with CYP3A4 substrates with a narrow therapeutic index may cause increased exposure of the CYP3A4 substrate and also increase CYP3A4 substrate adverse reactions. In a drug interaction study in healthy subjects, coadministration of ribociclib and midazolam (a sensitive CYP3A4 substrate) resulted in significant increases in midazolam Cmax and AUC. Monitor for increased adverse reactions of the CYP3A4 substrate during concomitant use. The dose of the CYP3A4 substrate may need to be reduced1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism by ribociclib
Literature reports
1 report — tap to read
a) Coadministration of ribociclib 400 mg once daily for 8 days with midazolam increased midazolam Cmax by 2.1-fold and AUC(inf) by 3.8-fold in a drug interaction study in healthy subjects. Administration of ribociclib at 600 mg once daily is predicted to increase midazolam Cmax by 2.4-fold and AUC by 5.2-fold 1.
Common questions
Can I take Clindamycin Vaginal and Ribociclib together?
Increased exposure of CYP3A4 substrate and an increased risk of CYP3A4 substrate-related adverse reactions Always confirm with your pharmacist or prescriber before making any change.
How serious is the Clindamycin Vaginal and Ribociclib 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 Clindamycin Vaginal or Ribociclib 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: KISQALI(R) oral tablets, ribociclib oral tablets. Novartis Pharmaceuticals Corporation (per FDA), East Hanover, NJ, 2025. DailyMed
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