Drug interactions
Chlorpromazine + Erythromycin base
Severity: Major
Chlorpromazine and Erythromycin base: 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
Erythromycin prolongs the QT interval and chlorpromazine does as well, so the combination raises the risk of torsades de pointes. Erythromycin may also raise chlorpromazine exposure by inhibiting its metabolism.
What this interaction means in plain words
Chlorpromazine and Erythromycin base 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 CYP3A4 inhibition by erythromycin.
What to do
Prefer a non-macrolide or less QT-active antibiotic such as azithromycin if suitable. If combined, monitor ECG and electrolytes.
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 Chlorpromazine
- Chlorpromazine + Dofetilide Contraindicated
- Chlorpromazine + Dronedarone Contraindicated
- Chlorpromazine + Droperidol Contraindicated
- Chlorpromazine + Ibutilide Contraindicated
- Chlorpromazine + Metrizamide Contraindicated
- Chlorpromazine + Panobinostat Contraindicated
Frequently asked questions
Can I take Chlorpromazine with Erythromycin base?
MediHelp rates the interaction as major. Chlorpromazine and Erythromycin base 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 prolongs the QT interval and chlorpromazine does as well, so the combination raises the risk of torsades de pointes. Erythromycin may also raise chlorpromazine exposure by inhibiting its metabolism.
How serious is the interaction between Chlorpromazine and Erythromycin base?
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 or less QT-active antibiotic such as azithromycin if suitable. If combined, monitor ECG and electrolytes.
What other medicines interact with Chlorpromazine?
MediHelp also lists interactions of Chlorpromazine with, for example, Dofetilide, Dronedarone, Droperidol. The full list is on the Chlorpromazine page.
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