Drug interactions
Siponimod + Voxelotor
Severity: Moderate
Siponimod and Voxelotor: 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
Voxelotor inhibits CYP3A4 and can raise exposure to drugs cleared by it. Siponimod is metabolised mainly by CYP2C9 with a smaller CYP3A4 contribution, so exposure may rise, increasing the risk of bradycardia, conduction effects, and other adverse effects.
What this interaction means in plain words
Siponimod and Voxelotor 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; Voxelotor belongs to Miscellaneous.
Why it happens
Voxelotor inhibits CYP3A4, reducing the minor CYP3A4-mediated clearance of siponimod.
What to do
Monitor heart rate and for siponimod adverse effects when voxelotor is started. Check the CYP2C9 genotype, since reduced CYP2C9 function increases the relative importance of CYP3A4 and magnifies the interaction.
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 Voxelotor
- Amobarbital + Voxelotor Major
- Apalutamide + Voxelotor Major
- Carbamazepine + Voxelotor Major
- Cyclosporin + Voxelotor Major
- Efavirenz + Voxelotor Major
- Enzalutamide + Voxelotor Major
Frequently asked questions
Can I take Siponimod with Voxelotor?
MediHelp rates the interaction as moderate. Siponimod and Voxelotor 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. Voxelotor inhibits CYP3A4 and can raise exposure to drugs cleared by it. Siponimod is metabolised mainly by CYP2C9 with a smaller CYP3A4 contribution, so exposure may rise, increasing the risk of bradycardia, conduction effects, and other adverse effects.
How serious is the interaction between Siponimod and Voxelotor?
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 for siponimod adverse effects when voxelotor is started. Check the CYP2C9 genotype, since reduced CYP2C9 function increases the relative importance of CYP3A4 and magnifies the interaction.
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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