Drug interactions
Samarium sm 153 lexidronam + Siponimod
Severity: Moderate
Samarium sm 153 lexidronam 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
Samarium-153 lexidronam is a bone-seeking radiopharmaceutical that suppresses bone marrow for several weeks. Siponimod lowers lymphocyte counts, so the combination may increase infection risk.
What this interaction means in plain words
Samarium sm 153 lexidronam 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.
Why it happens
Additive effects on blood counts: radiation-induced marrow suppression plus S1P receptor-mediated lymphocyte reduction.
What to do
Check complete blood counts weekly after samarium dosing until recovery. Monitor for infection and consider holding siponimod if marked cytopenias occur.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Samarium sm 153 lexidronam 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 14 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
Frequently asked questions
Can I take Samarium sm 153 lexidronam with Siponimod?
MediHelp rates the interaction as moderate. Samarium sm 153 lexidronam 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. Samarium-153 lexidronam is a bone-seeking radiopharmaceutical that suppresses bone marrow for several weeks. Siponimod lowers lymphocyte counts, so the combination may increase infection risk.
How serious is the interaction between Samarium sm 153 lexidronam 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: Check complete blood counts weekly after samarium dosing until recovery. Monitor for infection and consider holding siponimod if marked cytopenias occur.
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.
