Drug interactions
Foscarnet + Siponimod
Severity: Moderate
Foscarnet and Siponimod: moderate 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
Siponimod slows heart rate and conduction, particularly at initiation, and foscarnet may prolong QT and disturb electrolytes. Together they may increase arrhythmia risk.
What this interaction means in plain words
Foscarnet and Siponimod can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Foscarnet belongs to Anti Virals; Siponimod belongs to Central Nervous System.
Why it happens
Siponimod-induced bradycardia combined with foscarnet QT prolongation and electrolyte effects.
What to do
Obtain a baseline ECG and correct electrolytes; monitor heart rate and ECG, especially during siponimod initiation.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Foscarnet
- Cidofovir + Foscarnet Contraindicated
- Foscarnet + Pimozide Contraindicated
- Foscarnet + Thioridazine Contraindicated
- Foscarnet + Vandetanib Contraindicated
- Adagrasib + Foscarnet Major
- Adefovir + Foscarnet Major
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 Foscarnet with Siponimod?
MediHelp rates the interaction as moderate. Foscarnet and Siponimod can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Siponimod slows heart rate and conduction, particularly at initiation, and foscarnet may prolong QT and disturb electrolytes. Together they may increase arrhythmia risk.
How serious is the interaction between Foscarnet and Siponimod?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Obtain a baseline ECG and correct electrolytes; monitor heart rate and ECG, especially during siponimod initiation.
What other medicines interact with Foscarnet?
MediHelp also lists interactions of Foscarnet with, for example, Cidofovir, Pimozide, Thioridazine. The full list is on the Foscarnet page.
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