Drug interactions
Lefamulin + Primaquine
Severity: Major
Lefamulin and Primaquine: 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
Lefamulin is a CYP3A inhibitor and itself prolongs the QT interval. Primaquine has some QT-prolonging potential, so the combination may raise the risk of arrhythmia. The effect is mainly additive and is supported by exposure predictions.
What this interaction means in plain words
Lefamulin and Primaquine 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.
Lefamulin belongs to Anti Bacterial; Primaquine belongs to Anti Parasitic.
Why it happens
Additive QT prolongation, with possible increased primaquine exposure from CYP3A inhibition by lefamulin.
What to do
Avoid concurrent use where possible and select an alternative antibiotic. If both are needed, obtain a baseline ECG, correct potassium and magnesium, and monitor the QTc.
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 Primaquine
- Pimozide + Primaquine Contraindicated
- Amiodarone + Primaquine Major
- Amisulpride + Primaquine Major
- Anagrelide + Primaquine Major
- Arsenic trioxide + Primaquine Major
- Asenapine + Primaquine Major
Other interactions of Lefamulin
- Lefamulin + Methadone Contraindicated
- Lefamulin + Pimavanserin Contraindicated
- Lefamulin + Pimozide Contraindicated
- Lefamulin + Quinidine Contraindicated
- Alfuzosin + Lefamulin Major
- Amiodarone + Lefamulin Major
Frequently asked questions
Can I take Lefamulin with Primaquine?
MediHelp rates the interaction as major. Lefamulin and Primaquine 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. Lefamulin is a CYP3A inhibitor and itself prolongs the QT interval. Primaquine has some QT-prolonging potential, so the combination may raise the risk of arrhythmia. The effect is mainly additive and is supported by exposure predictions.
How serious is the interaction between Lefamulin and Primaquine?
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 concurrent use where possible and select an alternative antibiotic. If both are needed, obtain a baseline ECG, correct potassium and magnesium, and monitor the QTc.
What other medicines interact with Primaquine?
MediHelp also lists interactions of Primaquine with, for example, Pimozide, Amiodarone, Amisulpride. The full list is on the Primaquine page.
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