Drug interactions
Fedratinib + Siponimod
Severity: Major
Fedratinib 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
Fedratinib inhibits CYP3A4, which contributes to siponimod clearance, and may raise siponimod exposure. This effect is greater in patients with reduced CYP2C9 activity, who rely more on CYP3A4. Fedratinib may also cause myelosuppression, adding to lymphocyte reduction.
What this interaction means in plain words
Fedratinib 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.
Fedratinib belongs to Oncology; Siponimod belongs to Central Nervous System.
Why it happens
Inhibition of CYP3A4 reduces siponimod metabolism, and both drugs can lower immune cell counts.
What to do
Avoid the combination where possible, especially in CYP2C9*1/*3 or *2/*3 patients, for whom siponimod labeling restricts moderate CYP3A4/CYP2C9 dual inhibitors. If used, monitor blood counts, heart rate and infections.
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 Fedratinib
- Fedratinib + Thioridazine Contraindicated
- Amobarbital + Fedratinib Major
- Apalutamide + Fedratinib Major
- Brexpiprazole + Fedratinib Major
- Carbamazepine + Fedratinib Major
- Chloramphenicol + Fedratinib Major
Frequently asked questions
Can I take Fedratinib with Siponimod?
MediHelp rates the interaction as major. Fedratinib 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. Fedratinib inhibits CYP3A4, which contributes to siponimod clearance, and may raise siponimod exposure. This effect is greater in patients with reduced CYP2C9 activity, who rely more on CYP3A4. Fedratinib may also cause myelosuppression, adding to lymphocyte reduction.
How serious is the interaction between Fedratinib 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 the combination where possible, especially in CYP2C9*1/*3 or *2/*3 patients, for whom siponimod labeling restricts moderate CYP3A4/CYP2C9 dual inhibitors. If used, monitor blood counts, heart rate and infections.
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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