Ciprofloxacin and Elacestrant: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Ciprofloxacin
No brand names on recordElacestrant
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 elacestrant exposure and an increased risk of elacestrant-related adverse effects
Interaction Deep Dive
Avoid concomitant use of elacestrant with moderate CYP3A4 inhibitors. Concomitant use of elacestrant (a CYP3A4 substrate) with a moderate CYP3A4 inhibitor increases elacestrant exposure, which may increase the risk of elacestrant adverse reactions. In an interaction study, elacestrant Cmax increased by 1.6-fold and AUC increased by 2.3-fold following the concomitant use of elacestrant 345 mg single dose with fluconazole1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism of elacestrant
Literature reports
1 report — tap to read
a) In an interaction study, elacestrant Cmax increased by 1.6-fold and AUC increased by 2.3-fold following the concomitant use of elacestrant 345 mg single dose with fluconazole (a moderate CYP3A inhibitor) 1.
Common questions
Can I take Ciprofloxacin and Elacestrant together?
Increased elacestrant exposure and an increased risk of elacestrant-related adverse effects Always confirm with your pharmacist or prescriber before making any change.
How serious is the Ciprofloxacin and Elacestrant 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.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Ciprofloxacin or Elacestrant 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: ORSERDU(TM) oral tablets, elacestrant oral tablets. Stemline Therapeutics (per FDA), New York, NY, 2023. DailyMed
Keep reading about Ciprofloxacin
Keep reading about Elacestrant
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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