Drug interactions
Rifabutin + Siponimod
Severity: Major
Rifabutin 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
Rifabutin induces CYP3A4 and may lower siponimod concentrations, reducing efficacy. The effect is greater in patients with impaired CYP2C9 metabolism, where CYP3A4 is a larger clearance pathway.
What this interaction means in plain words
Rifabutin 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.
Rifabutin belongs to Anti Bacterial; Siponimod belongs to Central Nervous System.
Why it happens
CYP3A4 induction by rifabutin increases siponimod metabolism.
What to do
Avoid in patients with CYP2C9*1/*3 or *2/*3 genotypes, and avoid it with other moderate CYP2C9 inhibitors. Otherwise consider alternative anti-mycobacterial therapy and monitor MS control.
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 Rifabutin
- Cabotegravir + Rifabutin Contraindicated
- Lorlatinib + Rifabutin Contraindicated
- Rifabutin + Voriconazole Contraindicated
- Apixaban + Rifabutin Major
- Axitinib + Rifabutin Major
- Brexpiprazole + Rifabutin Major
Frequently asked questions
Can I take Rifabutin with Siponimod?
MediHelp rates the interaction as major. Rifabutin 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. Rifabutin induces CYP3A4 and may lower siponimod concentrations, reducing efficacy. The effect is greater in patients with impaired CYP2C9 metabolism, where CYP3A4 is a larger clearance pathway.
How serious is the interaction between Rifabutin 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 in patients with CYP2C9*1/*3 or *2/*3 genotypes, and avoid it with other moderate CYP2C9 inhibitors. Otherwise consider alternative anti-mycobacterial therapy and monitor MS control.
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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