Drug interactions
Moxifloxacin + Siponimod
Severity: Major
Moxifloxacin and Siponimod: major interaction.
Last updated Sources: Health Canada product monograph
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 can slow the heart rate and delay atrioventricular conduction at treatment initiation. Bradycardia increases vulnerability to torsades de pointes when combined with a QT-prolonging drug like moxifloxacin.
What this interaction means in plain words
Moxifloxacin 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.
Moxifloxacin belongs to Anti Bacterial; Siponimod belongs to Central Nervous System.
Why it happens
Siponimod-induced bradycardia combined with moxifloxacin QT prolongation raises proarrhythmic risk.
What to do
Avoid starting siponimod in patients taking QT-prolonging drugs unless specialist cardiology advice is obtained. If both are needed, perform an ECG and monitor heart rate during 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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References
Other interactions of Moxifloxacin
- Amiodarone + Moxifloxacin Contraindicated
- Arsenic trioxide + Moxifloxacin Contraindicated
- Disopyramide + Moxifloxacin Contraindicated
- Dofetilide + Moxifloxacin Contraindicated
- Dronedarone + Moxifloxacin Contraindicated
- Droperidol + Moxifloxacin 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 Moxifloxacin with Siponimod?
MediHelp rates the interaction as major. Moxifloxacin 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. Siponimod can slow the heart rate and delay atrioventricular conduction at treatment initiation. Bradycardia increases vulnerability to torsades de pointes when combined with a QT-prolonging drug like moxifloxacin.
How serious is the interaction between Moxifloxacin 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 starting siponimod in patients taking QT-prolonging drugs unless specialist cardiology advice is obtained. If both are needed, perform an ECG and monitor heart rate during initiation.
What other medicines interact with Moxifloxacin?
MediHelp also lists interactions of Moxifloxacin with, for example, Amiodarone, Arsenic trioxide, Disopyramide. The full list is on the Moxifloxacin page.
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