Drug interactions
Fexinidazole + Methadone
Severity: Major
Fexinidazole and Methadone: 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
Both drugs prolong the QT interval, so combining them raises the risk of torsades de pointes. Fexinidazole may also inhibit CYP3A4 and increase methadone exposure, adding to opioid and cardiac toxicity.
What this interaction means in plain words
Fexinidazole 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
Additive QT prolongation plus CYP3A4 inhibition by fexinidazole reducing methadone metabolism.
What to do
Avoid the combination if possible. If essential, perform an ECG, correct potassium and magnesium, and monitor for QT prolongation and opioid toxicity.
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
Frequently asked questions
Can I take Fexinidazole with Methadone?
MediHelp rates the interaction as major. Fexinidazole 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. Both drugs prolong the QT interval, so combining them raises the risk of torsades de pointes. Fexinidazole may also inhibit CYP3A4 and increase methadone exposure, adding to opioid and cardiac toxicity.
How serious is the interaction between Fexinidazole 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: Avoid the combination if possible. If essential, perform an ECG, correct potassium and magnesium, and monitor for QT prolongation and opioid toxicity.
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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