Gemfibrozil and Apalutamide: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Apalutamide
Gemfibrozil
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 apalutamide exposure
Interaction Deep Dive
Concomitant use of apalutamide and gemfibrozil (strong CYP2C8 inhibitor) may increase the exposure of apalutamide. Coadministration of a single dose of apalutamide 240 mg with gemfibrozil, a strong CYP2C8 inhibitor, resulted in an increase in apalutamide AUC by 68%. It is predicted that gemfibrozil will increase the steady-state apalutamide Cmax by 32% and AUC by 44%. The predicted steady-state Cmax for the active moieties (unbound apalutamide plus the potency-adjusted unbound N-desmethyl apalutamide) increased by 19% and the AUC increased by 23%. During coadministration, initial dosage adjustment of apalutamide is not needed; however, apalutamide dose reduction may become necessary based on tolerability. For other adverse reactions, including those that may be related to increased exposure to apalutamide due to drug interactions, resume apalutamide at the same dose or at a reduced dose (180 mg or 120 mg) when symptoms improve to less than or equal to Grade 1 or original grade, if warranted. If the apalutamide dose was reduced for an adverse reaction while receiving a drug that increases exposure to apalutamide, consider resuming the previously tolerated dose after the drug has been discontinued for at least 3 half-lives1.
Why it happens (mechanism)
Inhibition of CYP2C8-mediated metabolism of apalutamide
Literature reports
1 report — tap to read
a) Coadministration of a single dose of apalutamide 240 mg with gemfibrozil, a strong CYP2C8 inhibitor, resulted in an increase in apalutamide AUC by 68% while the Cmax decreased by 21%. It is predicted that gemfibrozil will increase the steady-state apalutamide Cmax by 32% and AUC by 44%. The predicted steady-state Cmax for the active moieties (unbound apalutamide plus the potency-adjusted unbound N-desmethyl apalutamide) increased by 19% and the AUC increased by 23% 1.
Common questions
Can I take Gemfibrozil and Apalutamide together?
Increased apalutamide exposure Always confirm with your pharmacist or prescriber before making any change.
How serious is the Gemfibrozil and Apalutamide 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 Gemfibrozil or Apalutamide 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® oral tablets, apalutamide oral tablets. Janssen Products LP (per FDA), Horsham, PA, 2026. DailyMed
Keep reading about Apalutamide
Keep reading about Gemfibrozil
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