Drug interactions
Methadone + Tucatinib
Severity: Major
Methadone and Tucatinib: major 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
Tucatinib is a strong CYP3A inhibitor and may raise methadone concentrations. Increased exposure could cause excess sedation, respiratory depression and QT prolongation.
What this interaction means in plain words
Methadone and Tucatinib can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Methadone belongs to Musculoskeletal; Tucatinib belongs to Oncology.
Why it happens
Tucatinib inhibits CYP3A4, reducing the metabolism of methadone.
What to do
Avoid the combination if possible; if needed, monitor for sedation, respiratory depression and QTc changes, and reduce the methadone dose as clinically indicated.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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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 Tucatinib
- Cisapride + Tucatinib Contraindicated
- Eletriptan + Tucatinib Contraindicated
- Ergotamine + Tucatinib Contraindicated
- Flibanserin + Tucatinib Contraindicated
- Ranolazine + Tucatinib Contraindicated
- Amobarbital + Tucatinib Major
Frequently asked questions
Can I take Methadone with Tucatinib?
MediHelp rates the interaction as major. Methadone and Tucatinib can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Tucatinib is a strong CYP3A inhibitor and may raise methadone concentrations. Increased exposure could cause excess sedation, respiratory depression and QT prolongation.
How serious is the interaction between Methadone and Tucatinib?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination if possible; if needed, monitor for sedation, respiratory depression and QTc changes, and reduce the methadone dose as clinically indicated.
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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