Cimetidine and Bosutinib: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Cimetidine
Bosutinib
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 or reduced bosutinib exposure
Interaction Deep Dive
Coadministration of bosutinib and cimetidine (a moderate CYP3A inhibitor) should be avoided as this may result in increased bosutinib plasma concentrations which may increase the risk of toxicities. Also, Coadministration of bosutinib and H2 antagonists such as cimetidine should be undertaken with caution as this may result in decreased plasma concentrations of bosutinib. Separate dosing of bosutinib and H2 antagonists by at least 2 hours1.
Why it happens (mechanism)
Inhibition of CYP3A-mediated bosutinib metabolism; interference with bosutinib absorption due to increased gastric pH caused by H2 antagonists
Literature reports
1 report — tap to read
a) In a cross-over drug interaction study in healthy volunteers (n=18), coadministration of single dose bosutinib 500 mg and aprepitant 125 mg resulted in a 2-fold increase in bosutinib AUC and a 1.5-fold increase in bosutinib Cmax 1.
Common questions
Can I take Cimetidine and Bosutinib together?
Increased or reduced bosutinib exposure Always confirm with your pharmacist or prescriber before making any change.
How serious is the Cimetidine and Bosutinib 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 Cimetidine or Bosutinib 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: BOSULIF(R) oral tablets oral capsules, bosutinib oral tablets oral capsules. Pfizer Labs (per FDA), New York, NY, 2023. DailyMed
Keep reading about Cimetidine
Keep reading about Bosutinib
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