Drug interactions
Hydroxyurea + Siponimod
Severity: Major
Hydroxyurea and Siponimod: major 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
Hydroxyurea is myelosuppressive and siponimod lowers lymphocytes. Together they may raise the risk of infection.
What this interaction means in plain words
Hydroxyurea and Siponimod can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Hydroxyurea belongs to Miscellaneous; Siponimod belongs to Central Nervous System.
Why it happens
Additive immunosuppression from ribonucleotide reductase inhibition-related myelosuppression and lymphocyte sequestration.
What to do
Avoid if possible; if combined, monitor complete blood counts and signs of infection regularly. Consider holding siponimod if counts fall significantly.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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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 Hydroxyurea
Frequently asked questions
Can I take Hydroxyurea with Siponimod?
MediHelp rates the interaction as major. Hydroxyurea and Siponimod can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Hydroxyurea is myelosuppressive and siponimod lowers lymphocytes. Together they may raise the risk of infection.
How serious is the interaction between Hydroxyurea and Siponimod?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid if possible; if combined, monitor complete blood counts and signs of infection regularly. Consider holding siponimod if counts fall significantly.
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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