Drug interactions
Erythromycin lactobionate + Fluoxetine
Severity: Major
Erythromycin lactobionate and Fluoxetine: 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
Intravenous erythromycin produces high concentrations and is a recognized cause of QT prolongation and torsades de pointes. Fluoxetine adds to this effect and the combination raises arrhythmia risk.
What this interaction means in plain words
Erythromycin lactobionate and Fluoxetine 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 lactobionate belongs to Anti Bacterial; Fluoxetine belongs to Central Nervous System.
Why it happens
Additive QT prolongation with possible pharmacokinetic contribution from CYP3A4 inhibition.
What to do
Consider a non-QT-prolonging antibiotic alternative. If combined, obtain an ECG, correct electrolytes and monitor rhythm during infusion.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Erythromycin lactobionate and Fluoxetine, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
References
Other interactions of Fluoxetine
- Fluoxetine + Isocarboxazid Contraindicated
- Fluoxetine + Mavacamten Contraindicated
- Fluoxetine + Methylene blue Contraindicated
- Fluoxetine + Phenelzine Contraindicated
- Fluoxetine + Pimozide Contraindicated
- Fluoxetine + Rasagiline Contraindicated
Other interactions of Erythromycin lactobionate
- Cisapride + Erythromycin lactobionate Contraindicated
- Dihydroergotamine + Erythromycin lactobionate Contraindicated
- Dronedarone + Erythromycin lactobionate Contraindicated
- Eletriptan + Erythromycin lactobionate Contraindicated
- Ergotamine + Erythromycin lactobionate Contraindicated
- Erythromycin lactobionate + Flibanserin Contraindicated
Frequently asked questions
Can I take Erythromycin lactobionate with Fluoxetine?
MediHelp rates the interaction as major. Erythromycin lactobionate and Fluoxetine 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. Intravenous erythromycin produces high concentrations and is a recognized cause of QT prolongation and torsades de pointes. Fluoxetine adds to this effect and the combination raises arrhythmia risk.
How serious is the interaction between Erythromycin lactobionate and Fluoxetine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Consider a non-QT-prolonging antibiotic alternative. If combined, obtain an ECG, correct electrolytes and monitor rhythm during infusion.
What other medicines interact with Fluoxetine?
MediHelp also lists interactions of Fluoxetine with, for example, Isocarboxazid, Mavacamten, Methylene blue. The full list is on the Fluoxetine page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
