Siponimod and Asciminib: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Jul 11, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Siponimod
Asciminib
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Increased CYP2C9 substrate exposure and an increased risk of CYP2C9 substrate-related adverse reactions
Interaction Deep Dive
Concomitant use of asciminib (a CYP2C9 inhibitor) with a CYP2C9 substrate increases the exposure of the CYP2C9 substrate, which may increase the risk of adverse reactions. Avoid coadministration of total doses of asciminib 80 mg/day with CYP2C9 substrates, where minimal concentration changes may lead to serious adverse reactions. If coadministration is unavoidable, reduce the CYP2C9 substrate dosage as recommended. Avoid coadministration of asciminib 200 mg twice daily with sensitive CYP2C9 substrates and CYP2C9 substrates, where minimal concentration changes may lead to serious adverse reactions. If coadministration is unavoidable, consider alternative therapy with a non-CYP2C9 substrate1.
Why it happens (mechanism)
Inhibition of CYP2C9-substrate metabolism by asciminib
Literature reports
1 report — tap to read
a) Coadministration of asciminib 40 mg twice daily with S-warfarin increased the AUC(inf) of S-warfarin by 41% and its Cmax by 8%. The S-warfarin AUC(inf) and Cmax increased by 52% and 4%, respectively, following coadministration with asciminib 80 mg once daily and by 314% and 7%, respectively, with 200 mg twice daily 1.
Common questions
Can I take Siponimod and Asciminib together?
Increased CYP2C9 substrate exposure and an increased risk of CYP2C9 substrate-related adverse reactions Always confirm with your pharmacist or prescriber before making any change.
How serious is the Siponimod and Asciminib interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Siponimod or Asciminib need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (1)
- Product Information: SCEMBLIX® oral tablets, asciminib oral tablets. Novartis Pharmaceuticals Corporation (per FDA), East Hanover, NJ, 2025. DailyMed
Keep reading about Siponimod
Keep reading about Asciminib
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