Drug interactions
Erythromycin lactobionate + Propafenone
Severity: Major
Erythromycin lactobionate and Propafenone: 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 inhibits CYP3A4 and raises propafenone concentrations, and both drugs can prolong the QT interval. This increases the risk of proarrhythmia, bradycardia and torsades de pointes.
What this interaction means in plain words
Erythromycin lactobionate and Propafenone 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; Propafenone belongs to Cardiovascular.
Why it happens
CYP3A4 inhibition by erythromycin reduces propafenone clearance, with additive QT effects.
What to do
Avoid if possible and choose a non-interacting antibiotic. If combined, monitor ECG and consider reducing the propafenone dose.
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 Propafenone
- Dofetilide + Propafenone Contraindicated
- Dronedarone + Propafenone Contraindicated
- Nilotinib + Propafenone Contraindicated
- Nirmatrelvir / ritonavir + Propafenone Contraindicated
- Nirmatrelvir + Propafenone Contraindicated
- Pimozide + Propafenone 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 Propafenone?
MediHelp rates the interaction as major. Erythromycin lactobionate and Propafenone 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 inhibits CYP3A4 and raises propafenone concentrations, and both drugs can prolong the QT interval. This increases the risk of proarrhythmia, bradycardia and torsades de pointes.
How serious is the interaction between Erythromycin lactobionate and Propafenone?
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 if possible and choose a non-interacting antibiotic. If combined, monitor ECG and consider reducing the propafenone dose.
What other medicines interact with Propafenone?
MediHelp also lists interactions of Propafenone with, for example, Dofetilide, Dronedarone, Nilotinib. The full list is on the Propafenone page.
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