Drug interactions
Erythromycin + Trazodone
Severity: Major
Erythromycin and Trazodone: 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
Both drugs can prolong the QT interval, and erythromycin may raise trazodone levels. Together they increase the risk of ventricular arrhythmias including torsades de pointes, especially with electrolyte disturbances or heart disease.
What this interaction means in plain words
Erythromycin and Trazodone 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; Trazodone belongs to Central Nervous System.
Why it happens
Additive QT prolongation plus CYP3A4 inhibition by erythromycin, raising trazodone exposure.
What to do
Prefer a non-QT-prolonging antibiotic. If coadministered, check ECG and electrolytes and consider a lower trazodone 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 Erythromycin
- Conivaptan + Erythromycin Contraindicated
- Dihydroergotamine intranasal + Erythromycin Contraindicated
- Dihydroergotamine + Erythromycin Contraindicated
- Domperidone + Erythromycin Contraindicated
- Dronedarone + Erythromycin Contraindicated
- Droperidol + Erythromycin Contraindicated
Other interactions of Trazodone
- Arsenic trioxide + Trazodone Contraindicated
- Ibutilide + Trazodone Contraindicated
- Isocarboxazid + Trazodone Contraindicated
- Levoketoconazole + Trazodone Contraindicated
- Methylene blue + Trazodone Contraindicated
- Phenelzine + Trazodone Contraindicated
Frequently asked questions
Can I take Erythromycin with Trazodone?
MediHelp rates the interaction as major. Erythromycin and Trazodone 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 the QT interval, and erythromycin may raise trazodone levels. Together they increase the risk of ventricular arrhythmias including torsades de pointes, especially with electrolyte disturbances or heart disease.
How serious is the interaction between Erythromycin and Trazodone?
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-QT-prolonging antibiotic. If coadministered, check ECG and electrolytes and consider a lower trazodone dose.
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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