Drug interactions
Methadone + Siponimod
Severity: Major
Methadone 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 causes transient heart rate slowing at initiation and methadone prolongs the QT interval. Bradycardia increases susceptibility to torsades de pointes, so the combination raises arrhythmia risk, particularly during siponimod titration.
What this interaction means in plain words
Methadone 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.
Methadone belongs to Musculoskeletal; Siponimod belongs to Central Nervous System.
Why it happens
Siponimod-induced bradycardia and conduction effects combine with methadone-related QT prolongation.
What to do
Obtain an ECG before starting siponimod and seek cardiology advice for patients on QT-prolonging drugs like methadone. Monitor heart rate and ECG during initiation, and consider an alternative to one of the agents if the QTc is prolonged.
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 Methadone
- Alvimopan + Methadone Contraindicated
- Calcium / magnesium / potassium / sodium oxybates + Methadone Contraindicated
- Droperidol + Methadone Contraindicated
- Ibutilide + Methadone Contraindicated
- Isocarboxazid + Methadone Contraindicated
- Lefamulin + Methadone 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 Methadone with Siponimod?
MediHelp rates the interaction as major. Methadone 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 causes transient heart rate slowing at initiation and methadone prolongs the QT interval. Bradycardia increases susceptibility to torsades de pointes, so the combination raises arrhythmia risk, particularly during siponimod titration.
How serious is the interaction between Methadone 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: Obtain an ECG before starting siponimod and seek cardiology advice for patients on QT-prolonging drugs like methadone. Monitor heart rate and ECG during initiation, and consider an alternative to one of the agents if the QTc is prolonged.
What other medicines interact with Methadone?
MediHelp also lists interactions of Methadone with, for example, Alvimopan, Calcium / magnesium / potassium / sodium oxybates, Droperidol. The full list is on the Methadone page.
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