Drug interactions
Siponimod + Tucatinib
Severity: Moderate
Siponimod 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 inhibits CYP3A4 and CYP2C8 and may raise siponimod exposure. Excess exposure increases bradyarrhythmia and other adverse effects.
What this interaction means in plain words
Siponimod 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.
Siponimod belongs to Central Nervous System; Tucatinib belongs to Oncology.
Why it happens
Inhibition of CYP3A4 reduces siponimod metabolism.
What to do
Monitor heart rate and adverse effects. Avoid in patients with reduced CYP2C9 function (e.g.
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 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 Siponimod with Tucatinib?
MediHelp rates the interaction as moderate. Siponimod 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 inhibits CYP3A4 and CYP2C8 and may raise siponimod exposure. Excess exposure increases bradyarrhythmia and other adverse effects.
How serious is the interaction between Siponimod 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 heart rate and adverse effects. Avoid in patients with reduced CYP2C9 function (e.g.
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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