Drug interactions
Bosentan + Tamoxifen
Severity: Moderate
Bosentan 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
Bosentan induces CYP3A4 and CYP2C9 and may lower concentrations of tamoxifen and its active metabolites. This could reduce antitumor efficacy.
What this interaction means in plain words
Bosentan 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.
Bosentan belongs to Miscellaneous; Tamoxifen belongs to Endocrine.
Why it happens
Bosentan induces CYP3A4 and CYP2C9, increasing tamoxifen metabolism.
What to do
Monitor for reduced response to tamoxifen and consider an alternative to bosentan if clinically appropriate.
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?
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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 Bosentan
- Bosentan + Cyclosporin Contraindicated
- Bosentan + Glibenclamide Contraindicated
- Bosentan + Glyburide-metformin Contraindicated
- Bosentan + Lonafarnib Contraindicated
- Bosentan + Sparsentan Contraindicated
- Artemether / lumefantrine + Bosentan Major
Frequently asked questions
Can I take Bosentan with Tamoxifen?
MediHelp rates the interaction as moderate. Bosentan 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. Bosentan induces CYP3A4 and CYP2C9 and may lower concentrations of tamoxifen and its active metabolites. This could reduce antitumor efficacy.
How serious is the interaction between Bosentan 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: Monitor for reduced response to tamoxifen and consider an alternative to bosentan if clinically appropriate.
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.
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