Drug Interaction Report

Gemfibrozil and Enzalutamide: Interaction Details

A pharmacist-reviewed analysis of the Gemfibrozil and Enzalutamide interaction: the documented clinical effects, severity rating, onset, mechanism, and management considerations, with cited references throughout.

AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Enzalutamide

Xtandi
+

Gemfibrozil

Lopid Lopid®
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Dr. Brian Staiger, PharmD, BCPS
Updated Aug 8, 2026
Editorial policy · Data sources
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Interaction severity
Major
Potentially serious — often needs a change or close monitoring.
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.

Of 80 documented Gemfibrozil interactions, 47 are rated major — including this one.
Worried about symptoms right now? Contact your pharmacist or prescriber, or call Poison Control at 1-800-222-1222 (US). Call 911 for an emergency.
Onset
unspecified
Evidence
probable
Severity
Major

What happens

Increased enzalutamide exposure, an increased risk of enzalutamide-related adverse reactions and an increased risk of seizures

Interaction Deep Dive

Avoid coadministration of enzalutamide and gemfibrozil (a strong CYP2C8 inhibitor), due to increased enzalutamide exposure, which may increase the incidence and severity of adverse reactions2, and may also increase the risk of seizures 1. If concomitant use cannot be avoided, reduce the dose of enzalutamide to 80 mg once daily. If concurrent gemfibrozil is discontinued, resume the enzalutamide dose used prior to initiation of gemfibrozil 2.

Why it happens (mechanism)

Inhibition of CYP2C8-mediated metabolism of enzalutamide

Literature reports

1 report — tap to read

a) Coadministration of multiple oral doses of gemfibrozil 600 mg twice a day with a single 160 mg dose of enzalutamide to healthy volunteers increased the AUC of enzalutamide and the major active metabolite, N-desmethyl enzalutamide, by 2.2-fold 12 and decreased Cmax by 16% 1.

Common questions

Can I take Gemfibrozil and Enzalutamide together?

Increased enzalutamide exposure, an increased risk of enzalutamide-related adverse reactions and an increased risk of seizures Always confirm with your pharmacist or prescriber before making any change.

How serious is the Gemfibrozil and Enzalutamide 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 Enzalutamide 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 (2)

  1. Product Information: LOPID(R) oral tablets, gemfibrozil oral tablets. Parke-Davis (per FDA), New York, NY, 2017. DailyMed
  2. Product Information: XTANDI® oral capsules, oral tablets, enzalutamide oral capsules, oral tablets. Astellas Pharma US Inc (per FDA), Northbrook, IL, 2025. DailyMed
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Enzalutamide

Keep reading about Enzalutamide

All Enzalutamide interactions (120)
Also serious with: Colchicine Lenacapavir Oral Doravirine Lurasidone
Gemfibrozil

Keep reading about Gemfibrozil

All Gemfibrozil interactions (80) Gemfibrozil drug information
Also serious with: Grazoprevir Ciprofibrate Dasabuvir Elagolix
Beyond drug–drug

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:

Enzalutamide + Activated Charcoal Alkanna Alpine Ragwort Black Tea Boneset Borage Butterbur Cannabidiol (cbd) + 41 more
Gemfibrozil + Activated Charcoal Beer Siberian Cocklebur Wine Ashwagandha Black Cohosh Boldo Buchu + 51 more

major · moderate · minor — check everything you take with our drug–supplement interaction checker.

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This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.