Drug interactions
Istradefylline + Modafinil
Severity: Minor
Istradefylline and Modafinil: 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
At the higher 40 mg daily dose, istradefylline inhibits CYP3A4 and may raise concentrations of CYP3A4 substrates such as modafinil. This may increase modafinil adverse effects, though the effect is modest.
What this interaction means in plain words
Istradefylline and Modafinil 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; Modafinil belongs to Central Nervous System.
Why it happens
Inhibition of CYP3A4 by istradefylline at higher doses reduces modafinil metabolism.
What to do
Monitor for modafinil adverse effects such as anxiety or insomnia, and reduce the modafinil dose if they occur.
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?
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Other interactions of Modafinil
Other interactions of Istradefylline
Frequently asked questions
Can I take Istradefylline with Modafinil?
MediHelp rates the interaction as minor. Istradefylline and Modafinil have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. At the higher 40 mg daily dose, istradefylline inhibits CYP3A4 and may raise concentrations of CYP3A4 substrates such as modafinil. This may increase modafinil adverse effects, though the effect is modest.
How serious is the interaction between Istradefylline and Modafinil?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor for modafinil adverse effects such as anxiety or insomnia, and reduce the modafinil dose if they occur.
What other medicines interact with Modafinil?
MediHelp also lists interactions of Modafinil with, for example, Lenacapavir, Leniolisib, Lorlatinib. The full list is on the Modafinil page.
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