Drug interactions
Bosentan + Siponimod
Severity: Major
Bosentan and Siponimod: major interaction.
Last updated Sources: US FDA label
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
Bosentan is a moderate CYP3A4 inducer and also induces CYP2C9, which may lower siponimod concentrations and reduce its efficacy in multiple sclerosis. The effect is greater in patients with CYP2C9*1/*3 or *2/*3 genotypes, in whom CYP3A4 carries a larger share of siponimod clearance.
What this interaction means in plain words
Bosentan 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.
Bosentan belongs to Miscellaneous; Siponimod belongs to Central Nervous System.
Why it happens
Induction of CYP3A4 and CYP2C9 by bosentan increases the metabolic clearance of siponimod.
What to do
Avoid the combination in patients with CYP2C9*1/*3 or *2/*3 genotype. In others, consider an alternative to bosentan and monitor for loss of disease 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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References
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 Bosentan
- Bosentan + Cyclosporin Contraindicated
- Bosentan + Glibenclamide Contraindicated
- Bosentan + Glyburide-metformin Contraindicated
- Bosentan + Lonafarnib Contraindicated
- Bosentan + Sparsentan Contraindicated
- Artemether / lumefantrine + Bosentan Major
Frequently asked questions
Can I take Bosentan with Siponimod?
MediHelp rates the interaction as major. Bosentan 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. Bosentan is a moderate CYP3A4 inducer and also induces CYP2C9, which may lower siponimod concentrations and reduce its efficacy in multiple sclerosis. The effect is greater in patients with CYP2C9*1/*3 or *2/*3 genotypes, in whom CYP3A4 carries a larger share of siponimod clearance.
How serious is the interaction between Bosentan 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 in patients with CYP2C9*1/*3 or *2/*3 genotype. In others, consider an alternative to bosentan and monitor for loss of disease 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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