Drug interactions
Istradefylline + Methotrexate
Severity: Moderate
Istradefylline and Methotrexate: 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
Istradefylline at higher doses inhibits P-glycoprotein and raised exposure of P-gp substrates in clinical studies. Methotrexate is a P-gp substrate, so its levels could increase modestly, with a risk of toxicity.
What this interaction means in plain words
Istradefylline and Methotrexate 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.
Istradefylline belongs to Central Nervous System; Methotrexate belongs to Oncology.
Why it happens
Inhibition of P-gp efflux increases methotrexate absorption and reduces its elimination.
What to do
Monitor blood counts and for methotrexate toxicity when starting istradefylline. Reduce the methotrexate dose if toxicity occurs.
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 Methotrexate
- Acitretin + Methotrexate Contraindicated
- Adenovirus types 4 and 7 live + Methotrexate Contraindicated
- Influenza virus vaccine quadrivalent intranasal + Methotrexate Contraindicated
- Ketorolac + Methotrexate Contraindicated
- Measles mumps and rubella vaccine live + Methotrexate Contraindicated
- Measles mumps and rubella vaccine + Methotrexate Contraindicated
Other interactions of Istradefylline
Frequently asked questions
Can I take Istradefylline with Methotrexate?
MediHelp rates the interaction as moderate. Istradefylline and Methotrexate 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. Istradefylline at higher doses inhibits P-glycoprotein and raised exposure of P-gp substrates in clinical studies. Methotrexate is a P-gp substrate, so its levels could increase modestly, with a risk of toxicity.
How serious is the interaction between Istradefylline and Methotrexate?
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 blood counts and for methotrexate toxicity when starting istradefylline. Reduce the methotrexate dose if toxicity occurs.
What other medicines interact with Methotrexate?
MediHelp also lists interactions of Methotrexate with, for example, Acitretin, Adenovirus types 4 and 7 live, Influenza virus vaccine quadrivalent intranasal. The full list is on the Methotrexate page.
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