Drug interactions
Pyrimethamine + Siponimod
Severity: Moderate
Pyrimethamine 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
Siponimod is cleared mainly by CYP2C9 with a contribution from CYP3A4. Pyrimethamine is not an established clinically significant CYP2C9 inhibitor, so any increase in siponimod exposure is uncertain.
What this interaction means in plain words
Pyrimethamine 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.
Pyrimethamine belongs to Anti Parasitic; Siponimod belongs to Central Nervous System.
Why it happens
Possible weak inhibition of CYP2C9-mediated siponimod metabolism; not well established.
What to do
Monitor for siponimod adverse effects such as bradycardia, infection and liver enzyme elevation. Ensure CYP2C9 genotype has been checked before siponimod therapy.
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?
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Other interactions of Pyrimethamine
- Deferiprone + Pyrimethamine Major
- Eliglustat + Pyrimethamine Major
- Acalabrutinib + Pyrimethamine Moderate
- Brexpiprazole + Pyrimethamine Moderate
- Dapsone + Pyrimethamine Moderate
- Folic acid + Pyrimethamine Moderate
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 Pyrimethamine with Siponimod?
MediHelp rates the interaction as moderate. Pyrimethamine 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. Siponimod is cleared mainly by CYP2C9 with a contribution from CYP3A4. Pyrimethamine is not an established clinically significant CYP2C9 inhibitor, so any increase in siponimod exposure is uncertain.
How serious is the interaction between Pyrimethamine 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: Monitor for siponimod adverse effects such as bradycardia, infection and liver enzyme elevation. Ensure CYP2C9 genotype has been checked before siponimod therapy.
What other medicines interact with Pyrimethamine?
MediHelp also lists interactions of Pyrimethamine with, for example, Deferiprone, Eliglustat, Acalabrutinib. The full list is on the Pyrimethamine page.
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