Gepotidacin and Abemaciclib: 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
Abemaciclib
Gepotidacin
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.
Your cancer medicine abemaciclib (Verzenio) is broken down in your body by an enzyme called CYP3A4. The antibiotic gepotidacin (Blujepa) can slow that enzyme down. When that happens, abemaciclib can build up higher than intended, which may increase side effects like diarrhea, low blood counts, tiredness, or nausea.
The good news is this is something your care team can plan for. Please don't stop or change either medicine on your own. Just let your pharmacist or doctor know you're taking both, and they can decide the safest approach and keep a closer eye on how you're doing.
Effect: Gepotidacin inhibits CYP3A4, reducing metabolism of CYP3A4 substrates and increasing their exposure. Abemaciclib is a CYP3A4 substrate, so co-administration may raise abemaciclib AUC/Cmax and the risk of dose-related toxicity (diarrhea, neutropenia, hepatotoxicity, fatigue).
Magnitude: With midazolam (probe substrate), supratherapeutic gepotidacin produced a ~1.9-fold increase in AUC.
Evidence: Probable. Onset: unspecified.
Management:
- Avoid concomitant use with narrow-therapeutic-index CYP3A4 substrates where feasible.
- If used together, dose may need individualization and closer monitoring for abemaciclib toxicity.
What happens
Increased CYP3A4 substrate with NTI exposure
Interaction Deep Dive
Do not combine gepotidacin with CYP3A4 substrates that have a narrow therapeutic index, since this pairing can raise exposure to the NTI CYP3A4 substrate. When midazolam, a CYP3A4 substrate, was given as a single 2 mg dose together with gepotidacin (administered as two 3,000 mg doses 12 hours apart, which is not an approved gepotidacin dosage), the midazolam AUC(0 to inf) rose by 1.9-fold1.
Why it happens (mechanism)
Inhibition of CYP3A4-substrate metabolism by gepotidacin
How to manage this interaction
Here is how a care team usually handles this:
- Avoiding the combination when possible is the preferred approach, since gepotidacin can raise abemaciclib levels.
- If both are needed, your team may adjust and individualize your dose and monitor you more closely for side effects.
What you can do:
- Keep taking both exactly as prescribed unless told otherwise.
- Tell your pharmacist or prescriber that you take both drugs before starting the antibiotic.
- Report new or worsening diarrhea, unusual tiredness, fever, or signs of infection.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) When midazolam (a CYP3A4 substrate) was given as a single 2 mg dose together with gepotidacin (administered as 2 doses of 3,000 mg, 12 hours apart; this is not an approved dosage of gepotidacin), the AUC(0 to inf) of midazolam rose by 1.9-fold 1.
Common questions
Can I take Gepotidacin and Abemaciclib together?
Gepotidacin can raise abemaciclib levels and side effects, so this combination is best avoided; check with your pharmacist or doctor before taking both, and don't change your medicines on your own. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Gepotidacin and Abemaciclib 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 Gepotidacin and Abemaciclib interaction managed?
Here is how a care team usually handles this: Avoiding the combination when possible is the preferred approach, since gepotidacin can raise abemaciclib levels. If both are needed, your team may adjust and individualize your dose and monitor you more closely for side effects. What you can do: Keep taking both exactly as prescribed unless told otherwise. Tell your pharmacist or prescriber that you t… 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 Gepotidacin or Abemaciclib 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: BLUJEPA oral tablets, gepotidacin oral tablets. GlaxoSmithKline (per FDA), Durham, NC, 2025. DailyMed
Keep reading about Abemaciclib
Keep reading about Gepotidacin
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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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