Drug interactions
Itraconazole + Lefamulin
Severity: Major
Itraconazole and Lefamulin: major interaction.
Last updated Sources: EMA SmPC
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
Itraconazole increases lefamulin exposure via CYP3A4 and P-gp inhibition, and both agents can prolong the QT interval. This raises the risk of QT-related arrhythmia.
What this interaction means in plain words
Itraconazole and Lefamulin 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.
Itraconazole belongs to Anti Fungals; Lefamulin belongs to Anti Bacterial.
Why it happens
Strong CYP3A4/P-gp inhibition raises lefamulin levels, with additive QT prolongation.
What to do
Avoid co-administration with oral lefamulin and choose an alternative antibacterial or antifungal. If unavoidable, monitor ECG and electrolytes.
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 Itraconazole
- Alfuzosin + Itraconazole Contraindicated
- Alprazolam + Itraconazole Contraindicated
- Avanafil + Itraconazole Contraindicated
- Conivaptan + Itraconazole Contraindicated
- Dihydroergotamine intranasal + Itraconazole Contraindicated
- Dihydroergotamine + Itraconazole Contraindicated
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 Itraconazole with Lefamulin?
MediHelp rates the interaction as major. Itraconazole and Lefamulin 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. Itraconazole increases lefamulin exposure via CYP3A4 and P-gp inhibition, and both agents can prolong the QT interval. This raises the risk of QT-related arrhythmia.
How serious is the interaction between Itraconazole and Lefamulin?
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 co-administration with oral lefamulin and choose an alternative antibacterial or antifungal. If unavoidable, monitor ECG and electrolytes.
What other medicines interact with Itraconazole?
MediHelp also lists interactions of Itraconazole with, for example, Alfuzosin, Alprazolam, Avanafil. The full list is on the Itraconazole page.
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