Olaparib and Mifepristone: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Mifepristone
Olaparib
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 olaparib exposure and an increased miFEPRIStone exposure
Interaction Deep Dive
Coadministration of miFEPRIStone (strong CYP3A inhibitor) (Korlym®) and olaparib (CYP3A substrates with NTI) is contraindicated as it may increase olaparib exposure. If coadministered, discontinuation or dose reduction of olaparib may be necessary1. However, exert caution when miFEPRIStone (Mifeprex®) is coadministered with olaparib (CYP3A substrates with NTI). Due to the slow elimination of miFEPRIStone from the body, such interaction may be observed for a prolonged period after its administration 2. Consider an alternative agent with less CYP3A inhibition 3. If coadministration is necessary, reduce olaparib tablet dosage to 150 mg twice daily 3. Coadministration of miFEPRIStone with olaparib (CYP3A4 inhibitor) may increase miFEPRIStone exposure. Wait at least 2 weeks after stopping miFEPRIStone before initiating olaparib. If coadministered, use the lowest effective dose possible. Limit miFEPRIStone to 900 mg 1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism of olaparib; inhibition of CYP3A4-mediated metabolism of miFEPRIStone
Literature reports
2 reports — tap to read
a) Pharmacokinetic simulations suggest that concomitant use of olaparib (a CYP3A4 substrate) and fluconazole (a moderate CYP3A4 inhibitor) may cause a 121% increase in olaparib AUC and a 14% increase in olaparib Cmax 3.
b) In a drug interaction study, coadministration of miFEPRIStone 1200 mg once daily for 10 days and simvastatin (CYP3A4 substrate) 80 mg single dose, resulted in increased simvastatin AUC and Cmax by 10.40-fold and 7.02-fold, respectively. Also resulted in increased simvastatin acid AUC and Cmax by 15.7-fold and 18.20, respectively 1.
Common questions
Can I take Olaparib and Mifepristone together?
Increased olaparib exposure and an increased miFEPRIStone exposure Always confirm with your pharmacist or prescriber before making any change.
How serious is the Olaparib and Mifepristone interaction?
It is rated contraindicated. These should generally not be used together.
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 Olaparib or Mifepristone 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 (3)
- Product Information: KORLYM(R) oral tablets, mifepristone oral tablets. Corcept Therapeutics Incorporated (per Dailmed), Redwood City, CA, 2024. DailyMed
- Product Information: MIFEPREX(R) oral tablets, mifepristone oral tablets. Danco Laboratories, LLC (per FDA), New York, NY, 2023. DailyMed
- Product Information: LYNPARZA(R) oral capsules, olaparib oral capsules. AstraZeneca Pharmaceuticals LP (per FDA), Wilmington, DE, 2017. DailyMed
Keep reading about Mifepristone
Keep reading about Olaparib
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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:
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