Drug interactions
Erythromycin base + Methadone
Severity: Major
Erythromycin base and Methadone: major interaction.
Last updated Sources: US FDA label
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
Erythromycin inhibits CYP3A4 and can raise methadone concentrations, increasing the risk of sedation and respiratory depression. Both drugs also prolong the QT interval, so arrhythmia risk is increased.
What this interaction means in plain words
Erythromycin base and Methadone 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.
Why it happens
CYP3A4 inhibition reducing methadone clearance plus additive QT prolongation.
What to do
Prefer a non-macrolide antibiotic such as one without CYP3A4 inhibition or QT effects. If used, monitor for sedation and respiratory depression, check ECG, and consider reducing methadone dose.
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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References
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
Frequently asked questions
Can I take Erythromycin base with Methadone?
MediHelp rates the interaction as major. Erythromycin base and Methadone 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. Erythromycin inhibits CYP3A4 and can raise methadone concentrations, increasing the risk of sedation and respiratory depression. Both drugs also prolong the QT interval, so arrhythmia risk is increased.
How serious is the interaction between Erythromycin base and Methadone?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Prefer a non-macrolide antibiotic such as one without CYP3A4 inhibition or QT effects. If used, monitor for sedation and respiratory depression, check ECG, and consider reducing methadone dose.
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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