Drug interactions
Tamoxifen + Tucatinib
Severity: Moderate
Tamoxifen and Tucatinib: 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
Tucatinib is a CYP2C8 substrate and a CYP3A inhibitor. Tamoxifen may inhibit CYP2C8 and raise tucatinib exposure, while tucatinib may raise tamoxifen exposure.
What this interaction means in plain words
Tamoxifen and Tucatinib 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.
Tamoxifen belongs to Endocrine; Tucatinib belongs to Oncology.
Why it happens
CYP2C8 inhibition by tamoxifen and CYP3A inhibition by tucatinib.
What to do
Monitor for tucatinib toxicity such as diarrhea and hepatotoxicity, with liver tests. Reduce the tucatinib dose if adverse effects emerge.
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 Tamoxifen and Tucatinib, 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 14 days on the web. No card needed.
Other interactions of Tamoxifen
- Amiodarone + Tamoxifen Major
- Anastrozole + Tamoxifen Major
- Bupropion + Tamoxifen Major
- Carbamazepine + Tamoxifen Major
- Cinacalcet + Tamoxifen Major
- Dacomitinib + Tamoxifen Major
Other interactions of Tucatinib
- Cisapride + Tucatinib Contraindicated
- Eletriptan + Tucatinib Contraindicated
- Ergotamine + Tucatinib Contraindicated
- Flibanserin + Tucatinib Contraindicated
- Ranolazine + Tucatinib Contraindicated
- Amobarbital + Tucatinib Major
Frequently asked questions
Can I take Tamoxifen with Tucatinib?
MediHelp rates the interaction as moderate. Tamoxifen and Tucatinib 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. Tucatinib is a CYP2C8 substrate and a CYP3A inhibitor. Tamoxifen may inhibit CYP2C8 and raise tucatinib exposure, while tucatinib may raise tamoxifen exposure.
How serious is the interaction between Tamoxifen and Tucatinib?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor for tucatinib toxicity such as diarrhea and hepatotoxicity, with liver tests. Reduce the tucatinib dose if adverse effects emerge.
What other medicines interact with Tamoxifen?
MediHelp also lists interactions of Tamoxifen with, for example, Amiodarone, Anastrozole, Bupropion. The full list is on the Tamoxifen 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.
