Drug interactions
Cimetidine + Erythromycin lactobionate
Severity: Moderate
Cimetidine and Erythromycin lactobionate: moderate 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
Cimetidine can raise erythromycin concentrations. With intravenous dosing this may add to QT prolongation and ototoxicity risk.
What this interaction means in plain words
Cimetidine and Erythromycin lactobionate can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Cimetidine belongs to Gastrointestinal Tract; Erythromycin lactobionate belongs to Anti Bacterial.
Why it happens
Cimetidine inhibits CYP3A4, reducing erythromycin metabolism.
What to do
Monitor the ECG and QTc in patients with cardiac risk factors or other QT-prolonging drugs. Use famotidine as an alternative where appropriate.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Cimetidine and Erythromycin lactobionate, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Cimetidine
- Cimetidine + Dofetilide Contraindicated
- Cimetidine + Fezolinetant Contraindicated
- Alfentanil + Cimetidine Major
- Atazanavir + Cimetidine Major
- Carmustine + Cimetidine Major
- Cimetidine + Citalopram Major
Other interactions of Erythromycin lactobionate
- Cisapride + Erythromycin lactobionate Contraindicated
- Dihydroergotamine + Erythromycin lactobionate Contraindicated
- Dronedarone + Erythromycin lactobionate Contraindicated
- Eletriptan + Erythromycin lactobionate Contraindicated
- Ergotamine + Erythromycin lactobionate Contraindicated
- Erythromycin lactobionate + Flibanserin Contraindicated
Frequently asked questions
Can I take Cimetidine with Erythromycin lactobionate?
MediHelp rates the interaction as moderate. Cimetidine and Erythromycin lactobionate can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Cimetidine can raise erythromycin concentrations. With intravenous dosing this may add to QT prolongation and ototoxicity risk.
How serious is the interaction between Cimetidine and Erythromycin lactobionate?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor the ECG and QTc in patients with cardiac risk factors or other QT-prolonging drugs. Use famotidine as an alternative where appropriate.
What other medicines interact with Cimetidine?
MediHelp also lists interactions of Cimetidine with, for example, Dofetilide, Fezolinetant, Alfentanil. The full list is on the Cimetidine page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
