Drug Interaction Report

Bosutinib and Ribociclib: Interaction Details

AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Ribociclib

Kisqali
+

Bosutinib

Bosulif Bosulif®
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Updated Aug 8, 2026
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Interaction severity
Major
Potentially serious — often needs a change or close monitoring.
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.

Of 164 documented Bosutinib interactions, 125 are rated major — including this one.
Worried about symptoms right now? Contact your pharmacist or prescriber, or call Poison Control at 1-800-222-1222 (US). Call 911 for an emergency.
Onset
unspecified
Evidence
probable
Severity
Major

What happens

Increased bosutinib exposure

Interaction Deep Dive

Avoid coadministration of bosutinib and a moderate or strong CYP3A inhibitor as this may result in increased bosutinib exposure which may increase the risk of toxicities. During drug interaction studies, coadministration of bosutinib and ketoconazole (a strong CYP3A inhibitor) resulted in increases in bosutinib AUC and Cmax1.

Why it happens (mechanism)

Inhibition of CYP3A-mediated bosutinib metabolism

Literature reports

1 report — tap to read

a) During cross-over drug interaction studies in healthy volunteers (n=24), coadministration of single dose bosutinib 100 mg and ketoconazole 400 mg/day for 5 days under fasted conditions resulted in an 8.6-fold increase in bosutinib AUC and a 5.2-fold increase in bosutinib Cmax 1.

Common questions

Can I take Bosutinib and Ribociclib together?

Increased bosutinib exposure Always confirm with your pharmacist or prescriber before making any change.

How serious is the Bosutinib 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 "probable". Good supporting evidence, though not definitively proven.

Questions for your pharmacist

  • Does my dose of Bosutinib 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)

  1. Product Information: BOSULIF(R) oral tablets oral capsules, bosutinib oral tablets oral capsules. Pfizer Labs (per FDA), New York, NY, 2023. DailyMed
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Beyond drug–drug

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.

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This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.