Apalutamide and Avatrombopag: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Jul 11, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Apalutamide
Avatrombopag
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 CYP3A4/CYP2C9 substrate exposure
Interaction Deep Dive
Concomitant use of apalutamide with CYP3A4/CYP2C9 substrates may result in reduced substrates exposure. In studies, coadministration of apalutamide with midazolam (CYP3A4 substrate) resulted in decreased apalutamide exposure. Also, coadministration of a single dose of apalutamide with S-warfarin, CYP2C9 substrate, resulted in a 46% decrease in the S-warfarin AUC. Substitution of the medication primarily metabolized by CYP3A4/CYP2C19 is recommended during apalutamide therapy. If coadministration is required, evaluate patient for loss of substrate activity1.
Why it happens (mechanism)
Induction of CYP3A4-substrate metabolism by apalutamide; induction of CYP2C9-substrate metabolism by apalutamide
Literature reports
2 reports — tap to read
Common questions
Can I take Apalutamide and Avatrombopag together?
Reduced CYP3A4/CYP2C9 substrate exposure Always confirm with your pharmacist or prescriber before making any change.
How serious is the Apalutamide and Avatrombopag 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 Apalutamide or Avatrombopag 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: ERLEADA(R) oral tablets, apalutamide oral tablets. Janssen Products LP (per FDA), Horsham, PA, 2024. DailyMed
Keep reading about Apalutamide
Keep reading about Avatrombopag
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