Drug interactions
Istradefylline + Siponimod
Severity: Minor
Istradefylline and Siponimod: minor 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
Istradefylline at 40 mg daily weakly inhibits CYP3A4 and may modestly raise exposure to CYP3A4 substrates. Siponimod is metabolised mainly by CYP2C9 and partly CYP3A4, so the effect is likely small except in CYP2C9-poor metabolisers.
What this interaction means in plain words
Istradefylline and Siponimod have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Istradefylline belongs to Central Nervous System; Siponimod belongs to Central Nervous System.
Why it happens
Weak CYP3A4 inhibition by istradefylline at higher doses reduces siponimod clearance.
What to do
No routine adjustment is needed. In CYP2C9*3 carriers, monitor heart rate and lymphocyte counts.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Istradefylline 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 Istradefylline
Frequently asked questions
Can I take Istradefylline with Siponimod?
MediHelp rates the interaction as minor. Istradefylline and Siponimod have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Istradefylline at 40 mg daily weakly inhibits CYP3A4 and may modestly raise exposure to CYP3A4 substrates. Siponimod is metabolised mainly by CYP2C9 and partly CYP3A4, so the effect is likely small except in CYP2C9-poor metabolisers.
How serious is the interaction between Istradefylline and Siponimod?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No routine adjustment is needed. In CYP2C9*3 carriers, monitor heart rate and lymphocyte counts.
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.
