Drug interactions
Erythromycin base + Quetiapine
Severity: Major
Erythromycin base and Quetiapine: 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
Erythromycin inhibits CYP3A4, the main route of quetiapine clearance, so quetiapine exposure rises. This can cause excessive sedation, hypotension and QT prolongation, and erythromycin itself also prolongs QT.
What this interaction means in plain words
Erythromycin base 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.
Why it happens
CYP3A4 inhibition reduces quetiapine metabolism, combined with additive QT-prolonging effects.
What to do
Prefer a non-interacting antibiotic such as a non-macrolide agent. If the combination is needed, lower 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 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 base with Quetiapine?
MediHelp rates the interaction as major. Erythromycin base 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 inhibits CYP3A4, the main route of quetiapine clearance, so quetiapine exposure rises. This can cause excessive sedation, hypotension and QT prolongation, and erythromycin itself also prolongs QT.
How serious is the interaction between Erythromycin base 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: Prefer a non-interacting antibiotic such as a non-macrolide agent. If the combination is needed, lower the quetiapine dose and monitor sedation, blood pressure and ECG.
What other medicines interact with Quetiapine?
MediHelp also lists interactions of Quetiapine with, for example, Adagrasib, Amiodarone, Amisulpride. The full list is on the Quetiapine page.
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