Drug interactions
Erythromycin + Flecainide
Severity: Major
Erythromycin and Flecainide: major interaction.
Last updated
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
Both drugs can prolong cardiac repolarization and conduction. Used together they may raise the risk of QT prolongation, ventricular arrhythmias and torsades de pointes, especially with structural heart disease or electrolyte disturbances.
What this interaction means in plain words
Erythromycin and Flecainide 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 belongs to Anti Bacterial; Flecainide belongs to Cardiovascular.
Why it happens
Additive pharmacodynamic effects on cardiac conduction and QT interval; erythromycin may also modestly raise flecainide exposure through CYP inhibition.
What to do
Prefer a non-macrolide antibiotic where possible; if combined, obtain a baseline and follow-up 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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Other interactions of Erythromycin
- Conivaptan + Erythromycin Contraindicated
- Dihydroergotamine intranasal + Erythromycin Contraindicated
- Dihydroergotamine + Erythromycin Contraindicated
- Domperidone + Erythromycin Contraindicated
- Dronedarone + Erythromycin Contraindicated
- Droperidol + Erythromycin Contraindicated
Other interactions of Flecainide
- Flecainide + Nirmatrelvir Contraindicated
- Flecainide + Nirmatrelvir / ritonavir Contraindicated
- Flecainide + Pimozide Contraindicated
- Flecainide + Ritonavir Contraindicated
- Flecainide + Thioridazine Contraindicated
- Flecainide + Tipranavir Contraindicated
Frequently asked questions
Can I take Erythromycin with Flecainide?
MediHelp rates the interaction as major. Erythromycin and Flecainide 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. Both drugs can prolong cardiac repolarization and conduction. Used together they may raise the risk of QT prolongation, ventricular arrhythmias and torsades de pointes, especially with structural heart disease or electrolyte disturbances.
How serious is the interaction between Erythromycin and Flecainide?
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-macrolide antibiotic where possible; if combined, obtain a baseline and follow-up ECG and correct potassium and magnesium.
What other medicines interact with Erythromycin?
MediHelp also lists interactions of Erythromycin with, for example, Conivaptan, Dihydroergotamine intranasal, Dihydroergotamine. The full list is on the Erythromycin page.
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