Drug interactions
Posaconazole + Siponimod
Severity: Major
Posaconazole 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
Posaconazole may increase siponimod exposure, intensifying bradycardia, infection risk and other effects. Both drugs can also affect cardiac conduction and QT.
What this interaction means in plain words
Posaconazole 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.
Posaconazole belongs to Anti Fungals; Siponimod belongs to Central Nervous System.
Why it happens
Posaconazole inhibits CYP3A4, which contributes to siponimod metabolism (alongside CYP2C9), with additive cardiac effects.
What to do
Avoid if possible, especially in CYP2C9*2/*3 or *3/*3 patients. If used, monitor heart rate and ECG, particularly at siponimod initiation.
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 Posaconazole
- Artemether + Posaconazole Contraindicated
- Avanafil + Posaconazole Contraindicated
- Cobimetinib + Posaconazole Contraindicated
- Conivaptan + Posaconazole Contraindicated
- Dihydroergotamine intranasal + Posaconazole Contraindicated
- Dihydroergotamine + Posaconazole Contraindicated
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
Frequently asked questions
Can I take Posaconazole with Siponimod?
MediHelp rates the interaction as major. Posaconazole 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. Posaconazole may increase siponimod exposure, intensifying bradycardia, infection risk and other effects. Both drugs can also affect cardiac conduction and QT.
How serious is the interaction between Posaconazole 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, especially in CYP2C9*2/*3 or *3/*3 patients. If used, monitor heart rate and ECG, particularly at siponimod initiation.
What other medicines interact with Posaconazole?
MediHelp also lists interactions of Posaconazole with, for example, Artemether, Avanafil, Cobimetinib. The full list is on the Posaconazole page.
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