Drug interactions
Diltiazem + Erythromycin base
Severity: Major
Diltiazem and Erythromycin base: 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
Both drugs inhibit CYP3A4 and each can raise the other's levels. This may produce hypotension, bradycardia and AV block from diltiazem, and QT prolongation from erythromycin.
What this interaction means in plain words
Diltiazem 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
Mutual inhibition of CYP3A4 metabolism.
What to do
Use an alternative antibiotic such as azithromycin where appropriate. If combined, monitor heart rate, 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 Diltiazem
- Diltiazem + Flibanserin Contraindicated
- Diltiazem + Ivabradine Contraindicated
- Diltiazem + Lomitapide Contraindicated
- Diltiazem + Lonafarnib Contraindicated
- Acebutolol + Diltiazem Major
- Alfentanil + Diltiazem Major
Frequently asked questions
Can I take Diltiazem with Erythromycin base?
MediHelp rates the interaction as major. Diltiazem 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. Both drugs inhibit CYP3A4 and each can raise the other's levels. This may produce hypotension, bradycardia and AV block from diltiazem, and QT prolongation from erythromycin.
How serious is the interaction between Diltiazem 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 an alternative antibiotic such as azithromycin where appropriate. If combined, monitor heart rate, blood pressure and ECG.
What other medicines interact with Diltiazem?
MediHelp also lists interactions of Diltiazem with, for example, Flibanserin, Ivabradine, Lomitapide. The full list is on the Diltiazem page.
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