Drug interactions
Lefamulin + Quinidine
Severity: Contraindicated
Lefamulin and Quinidine: contraindicated 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
Lefamulin prolongs the QT interval and inhibits CYP3A4, and quinidine is a QT-prolonging CYP3A substrate. Exposure to quinidine may rise, increasing the risk of torsades de pointes.
What this interaction means in plain words
Lefamulin and Quinidine are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two.
Lefamulin belongs to Anti Bacterial; Quinidine belongs to Anti Parasitic.
Why it happens
Lefamulin CYP3A4 inhibition raises quinidine levels, with additive QT prolongation.
What to do
Avoid concurrent use and choose an alternative antibacterial without QT effects. If treatment is essential, use ECG and electrolyte monitoring.
What to ask your pharmacist
- Is there an alternative to one of these two medicines for me?
- If both are essential, who is monitoring me and how often?
- Which symptoms mean I should stop and seek help straight away?
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Other interactions of Quinidine
- Adagrasib + Quinidine Contraindicated
- Arsenic trioxide + Quinidine Contraindicated
- Artemether / lumefantrine + Quinidine Contraindicated
- Chloroquine + Quinidine Contraindicated
- Dofetilide + Quinidine Contraindicated
- Dronedarone + Quinidine Contraindicated
Other interactions of Lefamulin
- Lefamulin + Methadone Contraindicated
- Lefamulin + Pimavanserin Contraindicated
- Lefamulin + Pimozide Contraindicated
- Alfuzosin + Lefamulin Major
- Amiodarone + Lefamulin Major
- Amisulpride + Lefamulin Major
Frequently asked questions
Can I take Lefamulin with Quinidine?
MediHelp rates the interaction as contraindicated. Lefamulin and Quinidine are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two. Lefamulin prolongs the QT interval and inhibits CYP3A4, and quinidine is a QT-prolonging CYP3A substrate. Exposure to quinidine may rise, increasing the risk of torsades de pointes.
How serious is the interaction between Lefamulin and Quinidine?
MediHelp rates it contraindicated, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid concurrent use and choose an alternative antibacterial without QT effects. If treatment is essential, use ECG and electrolyte monitoring.
What other medicines interact with Quinidine?
MediHelp also lists interactions of Quinidine with, for example, Adagrasib, Arsenic trioxide, Artemether / lumefantrine. The full list is on the Quinidine page.
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