Drug interactions
Citalopram + Erythromycin base
Severity: Major
Citalopram and Erythromycin base: major interaction.
Last updated Sources: Health Canada product monograph
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 inhibits CYP3A4, and citalopram is partly metabolized by CYP3A4. The combination increases the risk of torsades de pointes.
What this interaction means in plain words
Citalopram 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 QTc prolongation, with erythromycin's CYP3A4 inhibition raising citalopram levels.
What to do
Use a non-QT-prolonging antibiotic such as amoxicillin when appropriate. If erythromycin is necessary, obtain an ECG and correct 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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References
Other interactions of Citalopram
- Cisapride + Citalopram Contraindicated
- Citalopram + Dronedarone Contraindicated
- Citalopram + Escitalopram Contraindicated
- Citalopram + Isocarboxazid Contraindicated
- Citalopram + Methylene blue Contraindicated
- Citalopram + Phenelzine Contraindicated
Frequently asked questions
Can I take Citalopram with Erythromycin base?
MediHelp rates the interaction as major. Citalopram 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 inhibits CYP3A4, and citalopram is partly metabolized by CYP3A4. The combination increases the risk of torsades de pointes.
How serious is the interaction between Citalopram 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: Use a non-QT-prolonging antibiotic such as amoxicillin when appropriate. If erythromycin is necessary, obtain an ECG and correct electrolytes.
What other medicines interact with Citalopram?
MediHelp also lists interactions of Citalopram with, for example, Cisapride, Dronedarone, Escitalopram. The full list is on the Citalopram page.
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