Drug interactions
Istradefylline + Methadone
Severity: Minor
Istradefylline and Methadone: 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 weakly inhibits CYP3A4 and may increase methadone exposure. At 20 mg daily the effect is not expected to be significant.
What this interaction means in plain words
Istradefylline and Methadone 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; Methadone belongs to Musculoskeletal.
Why it happens
Istradefylline weakly inhibits CYP3A4 at higher doses, which reduces methadone metabolism.
What to do
Monitor for sedation and respiratory depression if the 40 mg dose is used. Consider lowering the methadone dose if signs of excess opioid effect 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 Methadone
- Alvimopan + Methadone Contraindicated
- Calcium / magnesium / potassium / sodium oxybates + Methadone Contraindicated
- Droperidol + Methadone Contraindicated
- Ibutilide + Methadone Contraindicated
- Isocarboxazid + Methadone Contraindicated
- Lefamulin + Methadone Contraindicated
Other interactions of Istradefylline
Frequently asked questions
Can I take Istradefylline with Methadone?
MediHelp rates the interaction as minor. Istradefylline and Methadone 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 weakly inhibits CYP3A4 and may increase methadone exposure. At 20 mg daily the effect is not expected to be significant.
How serious is the interaction between Istradefylline and Methadone?
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 sedation and respiratory depression if the 40 mg dose is used. Consider lowering the methadone dose if signs of excess opioid effect occur.
What other medicines interact with Methadone?
MediHelp also lists interactions of Methadone with, for example, Alvimopan, Calcium / magnesium / potassium / sodium oxybates, Droperidol. The full list is on the Methadone page.
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