Drug interactions
Clarithromycin + Siponimod
Severity: Major
Clarithromycin 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
Clarithromycin inhibits CYP3A4 and can raise siponimod exposure, especially in patients with reduced CYP2C9 activity. Siponimod can slow heart rate and affect cardiac conduction, and clarithromycin adds QT prolongation, so cardiac risk is increased.
What this interaction means in plain words
Clarithromycin 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.
Clarithromycin belongs to Anti Bacterial; Siponimod belongs to Central Nervous System.
Why it happens
CYP3A4 inhibition raises siponimod concentrations, plus additive effects on cardiac conduction and QT interval.
What to do
Avoid the combination in patients who are CYP2C9*3/*3 and prefer a non-interacting antibiotic. If used, monitor heart rate and ECG, particularly during a short course.
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 Clarithromycin
- Astemizole + Clarithromycin Contraindicated
- Avanafil + Clarithromycin Contraindicated
- Cisapride + Clarithromycin Contraindicated
- Clarithromycin + Colchicine Contraindicated
- Clarithromycin + Conivaptan Contraindicated
- Clarithromycin + Dihydroergotamine 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 Clarithromycin with Siponimod?
MediHelp rates the interaction as major. Clarithromycin 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. Clarithromycin inhibits CYP3A4 and can raise siponimod exposure, especially in patients with reduced CYP2C9 activity. Siponimod can slow heart rate and affect cardiac conduction, and clarithromycin adds QT prolongation, so cardiac risk is increased.
How serious is the interaction between Clarithromycin 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 in patients who are CYP2C9*3/*3 and prefer a non-interacting antibiotic. If used, monitor heart rate and ECG, particularly during a short course.
What other medicines interact with Clarithromycin?
MediHelp also lists interactions of Clarithromycin with, for example, Astemizole, Avanafil, Cisapride. The full list is on the Clarithromycin page.
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