Drug interactions
Fosaprepitant + Methadone
Severity: Minor
Fosaprepitant 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
Fosaprepitant is converted to aprepitant, a moderate CYP3A4 inhibitor. After a single dose the effect on methadone is usually small and short-lived, but methadone levels could rise slightly with opioid effects.
What this interaction means in plain words
Fosaprepitant 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.
Fosaprepitant belongs to Gastrointestinal Tract; Methadone belongs to Musculoskeletal.
Why it happens
Aprepitant transiently inhibits CYP3A4, which contributes to methadone metabolism.
What to do
No routine dose change is needed with single-dose use. Monitor for increased sedation over the following days, especially with repeated dosing.
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 Fosaprepitant
- Flibanserin + Fosaprepitant Contraindicated
- Fosaprepitant + Pimozide Contraindicated
- Alprazolam + Fosaprepitant Moderate
- Amiodarone + Fosaprepitant Moderate
- Amobarbital + Fosaprepitant Moderate
- Apalutamide + Fosaprepitant Moderate
Frequently asked questions
Can I take Fosaprepitant with Methadone?
MediHelp rates the interaction as minor. Fosaprepitant 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. Fosaprepitant is converted to aprepitant, a moderate CYP3A4 inhibitor. After a single dose the effect on methadone is usually small and short-lived, but methadone levels could rise slightly with opioid effects.
How serious is the interaction between Fosaprepitant 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: No routine dose change is needed with single-dose use. Monitor for increased sedation over the following days, especially with repeated dosing.
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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