Midostaurin and Voxelotor: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Voxelotor
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
Increased exposure of sensitive CYP3A4 substrates
Interaction Deep Dive
Avoid coadministration of voxelotor with sensitive CYP3A4 substrates with a narrow therapeutic index. If concomitant use is unavoidable, consider dose reduction of the sensitive CYP3A4 substrates. Voxelotor increased the systemic exposure of midazolam, a sensitive CYP3A4 substrate1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism by voxelotor
Literature reports
1 report — tap to read
a) Voxelotor inhibits CYP3A4 in vivo. The observed exposure increase of midazolam (CYP3A4 substrate) in healthy subjects was 1.6-fold, and the predicted increase in patients after multiple dosing is 2.5-fold 1.
Common questions
Can I take Midostaurin and Voxelotor together?
Increased exposure of sensitive CYP3A4 substrates Always confirm with your pharmacist or prescriber before making any change.
How serious is the Midostaurin and Voxelotor 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 Midostaurin or Voxelotor 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: OXBRYTA(R) oral tablets, tablets for oral suspension, voxelotor oral tablets, tablets for oral suspension. Global Blood Therapeutics Inc (per FDA), San Francisco, CA, 2023. DailyMed
Keep reading about Voxelotor
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.
Check another combination
Our instant two-drug interaction checker is almost here.
Still have questions about this combination?
Every question gets a real answer from a licensed pharmacist — free, and usually within a day.
Ask the pharmacist