Drug interactions
Erythromycin ethylsuccinate + Mifepristone
Severity: Major
Erythromycin ethylsuccinate and Mifepristone: major interaction.
Last updated Sources: Base de donnees publique des medicaments (France)
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
Mifepristone inhibits CYP3A4, and erythromycin is both a CYP3A4 substrate and a QT-prolonging macrolide. Higher erythromycin exposure may increase the risk of QT prolongation and arrhythmia. Erythromycin may in turn raise mifepristone levels.
What this interaction means in plain words
Erythromycin ethylsuccinate and Mifepristone 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
Mifepristone inhibits CYP3A4-mediated metabolism of erythromycin, with additive QT-prolonging effects.
What to do
Prefer a non-QT-prolonging antibiotic that is not a CYP3A4 substrate, such as a non-macrolide alternative. If combined, obtain an ECG and correct potassium and magnesium.
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 Mifepristone
- Apixaban + Mifepristone Contraindicated
- Argatroban + Mifepristone Contraindicated
- Cisapride + Mifepristone Contraindicated
- Cortisone + Mifepristone Contraindicated
- Cyclosporin + Mifepristone Contraindicated
- Dabigatran etexilate + Mifepristone Contraindicated
Frequently asked questions
Can I take Erythromycin ethylsuccinate with Mifepristone?
MediHelp rates the interaction as major. Erythromycin ethylsuccinate and Mifepristone 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. Mifepristone inhibits CYP3A4, and erythromycin is both a CYP3A4 substrate and a QT-prolonging macrolide. Higher erythromycin exposure may increase the risk of QT prolongation and arrhythmia. Erythromycin may in turn raise mifepristone levels.
How serious is the interaction between Erythromycin ethylsuccinate and Mifepristone?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Prefer a non-QT-prolonging antibiotic that is not a CYP3A4 substrate, such as a non-macrolide alternative. If combined, obtain an ECG and correct potassium and magnesium.
What other medicines interact with Mifepristone?
MediHelp also lists interactions of Mifepristone with, for example, Apixaban, Argatroban, Cisapride. The full list is on the Mifepristone page.
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