Drug interactions
Capecitabine + Siponimod
Severity: Moderate
Capecitabine and Siponimod: 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
Capecitabine is converted to fluorouracil, which has been reported to inhibit CYP2C9 (as seen with warfarin and phenytoin). This could raise siponimod exposure, although the effect on siponimod has not been well characterised.
What this interaction means in plain words
Capecitabine and Siponimod 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.
Capecitabine belongs to Oncology; Siponimod belongs to Central Nervous System.
Why it happens
Fluorouracil, the active metabolite of capecitabine, may inhibit CYP2C9, the main enzyme clearing siponimod.
What to do
Monitor for siponimod adverse effects such as bradycardia, lymphopenia and elevated liver enzymes, and check 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 Siponimod
- Cladribine + Siponimod Contraindicated
- Fingolimod + Siponimod Contraindicated
- Fluconazole + Siponimod Contraindicated
- Influenza virus vaccine quadrivalent intranasal + Siponimod Contraindicated
- Ponesimod + Siponimod Contraindicated
- Siponimod + Thioridazine Contraindicated
Other interactions of Capecitabine
Frequently asked questions
Can I take Capecitabine with Siponimod?
MediHelp rates the interaction as moderate. Capecitabine and Siponimod 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. Capecitabine is converted to fluorouracil, which has been reported to inhibit CYP2C9 (as seen with warfarin and phenytoin). This could raise siponimod exposure, although the effect on siponimod has not been well characterised.
How serious is the interaction between Capecitabine and Siponimod?
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 siponimod adverse effects such as bradycardia, lymphopenia and elevated liver enzymes, and check lymphocyte counts.
What other medicines interact with Siponimod?
MediHelp also lists interactions of Siponimod with, for example, Cladribine, Fingolimod, Fluconazole. The full list is on the Siponimod page.
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