Midostaurin and Tazemetostat: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Tazemetostat
Midostaurin
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
Reduced CYP3A substrate exposure and reduced efficacy of CYP3A substrate
Interaction Deep Dive
Concomitant use of tazemetostat with CYP3A substrates may reduce CYP3A substrates exposure leading to reduced efficacy of CYP3A substrates. In a drug interaction study, coadministration of tazemetostat 800 mg twice daily with oral midazolam (a sensitive CYP3A substrate) in patients decreased midazolam AUC and Cmax by 40% and 21%, respectively1.
Why it happens (mechanism)
Induction of CYP3A-substrate metabolism by tazemetostat
Literature reports
1 report — tap to read
a) In a drug interaction study, coadministration of tazemetostat 800 mg twice daily with oral midazolam (a sensitive CYP3A substrate) in patients decreased midazolam AUC and Cmax by 40% and 21%, respectively 1.
Common questions
Can I take Midostaurin and Tazemetostat together?
Reduced CYP3A substrate exposure and reduced efficacy of CYP3A substrate Always confirm with your pharmacist or prescriber before making any change.
How serious is the Midostaurin and Tazemetostat 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 "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Midostaurin or Tazemetostat 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: TAZVERIK(R) oral tablets, tazemetostat oral tablets. Epizyme Inc (per FDA), Cambridge, MA, 2024. DailyMed
Keep reading about Tazemetostat
Keep reading about Midostaurin
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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