Drug interactions
Lefamulin + Siponimod
Severity: Major
Lefamulin 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
Lefamulin is a moderate CYP3A inhibitor, and siponimod is metabolized by CYP2C9 and CYP3A4, so exposure may increase. Siponimod's bradycardia and conduction effects add to lefamulin's QT prolongation.
What this interaction means in plain words
Lefamulin 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.
Lefamulin belongs to Anti Bacterial; Siponimod belongs to Central Nervous System.
Why it happens
CYP3A inhibition by lefamulin raises siponimod exposure, with additive cardiac effects.
What to do
Avoid the combination if possible, particularly in patients with CYP2C9*1/*3 or *2/*3 genotype. Otherwise monitor ECG and heart rate.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Lefamulin and Siponimod, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
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 Lefamulin
- Lefamulin + Methadone Contraindicated
- Lefamulin + Pimavanserin Contraindicated
- Lefamulin + Pimozide Contraindicated
- Lefamulin + Quinidine Contraindicated
- Alfuzosin + Lefamulin Major
- Amiodarone + Lefamulin Major
Frequently asked questions
Can I take Lefamulin with Siponimod?
MediHelp rates the interaction as major. Lefamulin 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. Lefamulin is a moderate CYP3A inhibitor, and siponimod is metabolized by CYP2C9 and CYP3A4, so exposure may increase. Siponimod's bradycardia and conduction effects add to lefamulin's QT prolongation.
How serious is the interaction between Lefamulin 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 if possible, particularly in patients with CYP2C9*1/*3 or *2/*3 genotype. Otherwise monitor ECG and heart rate.
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.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
