Drug interactions
Erythromycin + Quetiapine
Severity: Major
Erythromycin and Quetiapine: major interaction.
Last updated Sources: UK SmPC
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 can substantially increase quetiapine concentrations, leading to excess sedation, hypotension and QT prolongation. Both drugs also affect cardiac repolarization, adding to arrhythmia risk.
What this interaction means in plain words
Erythromycin and Quetiapine 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; Quetiapine belongs to Central Nervous System.
Why it happens
Erythromycin inhibits CYP3A4, the main metabolic pathway of quetiapine, and both drugs have QT-prolonging potential.
What to do
Use a non-interacting antibiotic if possible. If coadministration is necessary, reduce the quetiapine dose and monitor sedation, blood pressure and ECG.
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 Erythromycin
- Conivaptan + Erythromycin Contraindicated
- Dihydroergotamine intranasal + Erythromycin Contraindicated
- Dihydroergotamine + Erythromycin Contraindicated
- Domperidone + Erythromycin Contraindicated
- Dronedarone + Erythromycin Contraindicated
- Droperidol + Erythromycin Contraindicated
Other interactions of Quetiapine
- Adagrasib + Quetiapine Major
- Amiodarone + Quetiapine Major
- Amisulpride + Quetiapine Major
- Amoxapine + Quetiapine Major
- Anagrelide + Quetiapine Major
- Apalutamide + Quetiapine Major
Frequently asked questions
Can I take Erythromycin with Quetiapine?
MediHelp rates the interaction as major. Erythromycin and Quetiapine 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 can substantially increase quetiapine concentrations, leading to excess sedation, hypotension and QT prolongation. Both drugs also affect cardiac repolarization, adding to arrhythmia risk.
How serious is the interaction between Erythromycin and Quetiapine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use a non-interacting antibiotic if possible. If coadministration is necessary, reduce the quetiapine dose and monitor sedation, blood pressure and ECG.
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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