Drug interactions
Tamoxifen + Vemurafenib
Severity: Moderate
Tamoxifen and Vemurafenib: 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
Tamoxifen may inhibit P-glycoprotein and raise vemurafenib exposure. This could increase vemurafenib toxicities such as rash, QT prolongation and liver injury.
What this interaction means in plain words
Tamoxifen and Vemurafenib 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; Vemurafenib belongs to Oncology.
Why it happens
Tamoxifen inhibits P-glycoprotein efflux of vemurafenib.
What to do
Monitor for vemurafenib adverse effects and ECG/electrolytes as indicated. Reduce vemurafenib dose if toxicity develops.
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 Vemurafenib, 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 Vemurafenib
Frequently asked questions
Can I take Tamoxifen with Vemurafenib?
MediHelp rates the interaction as moderate. Tamoxifen and Vemurafenib 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 may inhibit P-glycoprotein and raise vemurafenib exposure. This could increase vemurafenib toxicities such as rash, QT prolongation and liver injury.
How serious is the interaction between Tamoxifen and Vemurafenib?
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 vemurafenib adverse effects and ECG/electrolytes as indicated. Reduce vemurafenib dose if toxicity develops.
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.
