Drug interactions
Enzalutamide + Tamoxifen
Severity: Moderate
Enzalutamide and Tamoxifen: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Enzalutamide induces CYP3A4, which increases tamoxifen clearance and may reduce exposure to tamoxifen and its active metabolites. The clinical importance is uncertain, and the pair is rarely used together, but loss of endocrine efficacy is theoretically possible.
What this interaction means in plain words
Enzalutamide and Tamoxifen can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Enzalutamide belongs to Endocrine; Tamoxifen belongs to Endocrine.
Why it happens
CYP3A4 induction accelerates tamoxifen metabolism; the legacy suggestion of inhibition is incorrect since enzalutamide is an inducer, and the net effect on active metabolite endoxifen is uncertain.
What to do
Avoid concurrent use where an alternative endocrine strategy is available. If coadministered, monitor for reduced therapeutic response.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Enzalutamide and Tamoxifen, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Enzalutamide
- Doravirine + Enzalutamide Contraindicated
- Elbasvir / grazoprevir + Enzalutamide Contraindicated
- Ensitrelvir + Enzalutamide Contraindicated
- Enzalutamide + Fostemsavir Contraindicated
- Enzalutamide + Isavuconazonium Contraindicated
- Enzalutamide + Lenacapavir Contraindicated
Other interactions of Tamoxifen
- Amiodarone + Tamoxifen Major
- Anastrozole + Tamoxifen Major
- Bupropion + Tamoxifen Major
- Carbamazepine + Tamoxifen Major
- Cinacalcet + Tamoxifen Major
- Dacomitinib + Tamoxifen Major
Frequently asked questions
Can I take Enzalutamide with Tamoxifen?
MediHelp rates the interaction as moderate. Enzalutamide and Tamoxifen can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Enzalutamide induces CYP3A4, which increases tamoxifen clearance and may reduce exposure to tamoxifen and its active metabolites. The clinical importance is uncertain, and the pair is rarely used together, but loss of endocrine efficacy is theoretically possible.
How serious is the interaction between Enzalutamide and Tamoxifen?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid concurrent use where an alternative endocrine strategy is available. If coadministered, monitor for reduced therapeutic response.
What other medicines interact with Enzalutamide?
MediHelp also lists interactions of Enzalutamide with, for example, Doravirine, Elbasvir / grazoprevir, Ensitrelvir. The full list is on the Enzalutamide page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
