Istradefylline and Mitotane: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Mitotane
Istradefylline
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
Decreased istradefylline exposure
Interaction Deep Dive
Coadministration of istradefylline (a CYP34 substrate) with a strong CYP3A4 inducer (rifampin) reduced the istradefylline Cmax and AUC(infinity) by 45% and 81% respectively in a pharmacokinetic study. Avoid concurrent use of istradefylline and strong CYP3A4 inhibitors1.
Why it happens (mechanism)
Induction of CYP3A-mediated istradefylline metabolism
Literature reports
1 report — tap to read
a) Coadministration of rifampin (strong CYP3A4 inhibitor) 600 mg daily for 20 days with a single dose of istradefylline 40 mg reduced the Cmax and AUC(infinity) of istradefylline by 45% and 81% respectively, when compared with istradefylline administered alone 1.
Common questions
Can I take Istradefylline and Mitotane together?
Decreased istradefylline exposure Always confirm with your pharmacist or prescriber before making any change.
How serious is the Istradefylline and Mitotane 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 Istradefylline or Mitotane 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: NOURIANZ(TM) oral tablets, istradefylline oral tablets. Kyowa Kirin Inc (per FDA), Bedminster, NJ, 2019. DailyMed
Keep reading about Mitotane
Keep reading about Istradefylline
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