Drug interactions
Larotrectinib + Methadone
Severity: Minor
Larotrectinib 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
Larotrectinib is a weak CYP3A4 inhibitor in vitro, but a clinically important effect on methadone has not been established. Any increase in methadone exposure would likely be small.
What this interaction means in plain words
Larotrectinib 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.
Larotrectinib belongs to Oncology; Methadone belongs to Musculoskeletal.
Why it happens
Possible weak CYP3A4 inhibition by larotrectinib, which could slightly reduce methadone clearance.
What to do
No empirical dose change is needed. Monitor for sedation or other signs of excess opioid effect when starting larotrectinib.
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 Larotrectinib
Frequently asked questions
Can I take Larotrectinib with Methadone?
MediHelp rates the interaction as minor. Larotrectinib 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. Larotrectinib is a weak CYP3A4 inhibitor in vitro, but a clinically important effect on methadone has not been established. Any increase in methadone exposure would likely be small.
How serious is the interaction between Larotrectinib 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 empirical dose change is needed. Monitor for sedation or other signs of excess opioid effect when starting larotrectinib.
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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