Drug interactions
Erythromycin ethylsuccinate + Fluoxetine
Severity: Major
Erythromycin ethylsuccinate 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
Erythromycin is a recognized QT-prolonging macrolide and fluoxetine can add to this effect. Erythromycin also inhibits CYP3A4, so the combination raises arrhythmia risk.
What this interaction means in plain words
Erythromycin ethylsuccinate 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.
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, check ECG and electrolytes and monitor for palpitations or syncope.
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 Fluoxetine
- Fluoxetine + Isocarboxazid Contraindicated
- Fluoxetine + Mavacamten Contraindicated
- Fluoxetine + Methylene blue Contraindicated
- Fluoxetine + Phenelzine Contraindicated
- Fluoxetine + Pimozide Contraindicated
- Fluoxetine + Rasagiline Contraindicated
Frequently asked questions
Can I take Erythromycin ethylsuccinate with Fluoxetine?
MediHelp rates the interaction as major. Erythromycin ethylsuccinate 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 is a recognized QT-prolonging macrolide and fluoxetine can add to this effect. Erythromycin also inhibits CYP3A4, so the combination raises arrhythmia risk.
How serious is the interaction between Erythromycin ethylsuccinate 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, check ECG and electrolytes and monitor for palpitations or syncope.
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.
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