Drug interactions
Mefenamic acid + Siponimod
Severity: Moderate
Mefenamic acid 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
Mefenamic acid is a CYP2C9 substrate and can inhibit CYP2C9, the main enzyme clearing siponimod. Higher siponimod exposure may increase adverse effects such as bradyarrhythmia, infections and macular edema. Mefenamic acid is only a weak to moderate CYP2C9 inhibitor and does not inhibit CYP3A4, so the effect is likely modest.
What this interaction means in plain words
Mefenamic acid 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.
Mefenamic acid belongs to Musculoskeletal; Siponimod belongs to Central Nervous System.
Why it happens
Inhibition of CYP2C9-mediated siponimod metabolism raises siponimod plasma concentrations.
What to do
Confirm the patient's CYP2C9 genotype is suitable for siponimod and monitor heart rate and for signs of siponimod adverse effects. Consider another analgesic if prolonged NSAID use is required.
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 Mefenamic acid
- Ketorolac intranasal + Mefenamic acid Contraindicated
- Ketorolac + Mefenamic acid Contraindicated
- Aceclofenac + Mefenamic acid Major
- Acemetacin + Mefenamic acid Major
- Acetylsalicylic acid + Mefenamic acid Major
- Alteplase + Mefenamic acid Major
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 Mefenamic acid with Siponimod?
MediHelp rates the interaction as moderate. Mefenamic acid 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. Mefenamic acid is a CYP2C9 substrate and can inhibit CYP2C9, the main enzyme clearing siponimod. Higher siponimod exposure may increase adverse effects such as bradyarrhythmia, infections and macular edema. Mefenamic acid is only a weak to moderate CYP2C9 inhibitor and does not inhibit CYP3A4, so the effect is likely modest.
How serious is the interaction between Mefenamic acid 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: Confirm the patient's CYP2C9 genotype is suitable for siponimod and monitor heart rate and for signs of siponimod adverse effects. Consider another analgesic if prolonged NSAID use is required.
What other medicines interact with Mefenamic acid?
MediHelp also lists interactions of Mefenamic acid with, for example, Ketorolac intranasal, Ketorolac, Aceclofenac. The full list is on the Mefenamic acid page.
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