Drug interactions
Etrasimod + Tamoxifen
Severity: Moderate
Etrasimod 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
Etrasimod modulates sphingosine-1-phosphate receptors and lowers circulating lymphocytes, and its combination with an antineoplastic agent such as tamoxifen has not been studied for additive immune effects. Tamoxifen may also inhibit CYP2C8, which could raise etrasimod exposure, especially in CYP2C9 poor metabolizers.
What this interaction means in plain words
Etrasimod 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.
Etrasimod belongs to Gastrointestinal Tract; Tamoxifen belongs to Endocrine.
Why it happens
Possible additive immunosuppression plus CYP2C8 inhibition by tamoxifen reducing etrasimod clearance, mainly in CYP2C9 poor metabolizers.
What to do
Check CYP2C9 status if known and avoid the combination in CYP2C9 poor metabolizers. Otherwise monitor for infection and lymphocyte counts.
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 Etrasimod
- Abatacept + Etrasimod Major
- Amiodarone + Etrasimod Major
- Anagrelide + Etrasimod Major
- Anakinra + Etrasimod Major
- Anti-thymocyte + Etrasimod Major
- Asenapine + Etrasimod Major
Frequently asked questions
Can I take Etrasimod with Tamoxifen?
MediHelp rates the interaction as moderate. Etrasimod 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. Etrasimod modulates sphingosine-1-phosphate receptors and lowers circulating lymphocytes, and its combination with an antineoplastic agent such as tamoxifen has not been studied for additive immune effects. Tamoxifen may also inhibit CYP2C8, which could raise etrasimod exposure, especially in CYP2C9 poor metabolizers.
How serious is the interaction between Etrasimod 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: Check CYP2C9 status if known and avoid the combination in CYP2C9 poor metabolizers. Otherwise monitor for infection and lymphocyte counts.
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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