Drug interactions
Erythromycin + Quinupristin / dalfopristin
Severity: Major
Erythromycin and Quinupristin / dalfopristin: major 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
Quinupristin/dalfopristin inhibits CYP3A4 and may raise erythromycin levels, and both agents can prolong the QT interval. This raises the risk of ventricular arrhythmia. The combination also has no sound therapeutic rationale, since they act on overlapping ribosomal targets.
What this interaction means in plain words
Erythromycin and Quinupristin / dalfopristin 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 by dalfopristin/quinupristin with additive QT prolongation.
What to do
Avoid the combination if possible. If both are necessary, monitor ECG and 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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Other interactions of Erythromycin
- Conivaptan + Erythromycin Contraindicated
- Dihydroergotamine intranasal + Erythromycin Contraindicated
- Dihydroergotamine + Erythromycin Contraindicated
- Domperidone + Erythromycin Contraindicated
- Dronedarone + Erythromycin Contraindicated
- Droperidol + Erythromycin Contraindicated
Frequently asked questions
Can I take Erythromycin with Quinupristin / dalfopristin?
MediHelp rates the interaction as major. Erythromycin and Quinupristin / dalfopristin 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. Quinupristin/dalfopristin inhibits CYP3A4 and may raise erythromycin levels, and both agents can prolong the QT interval. This raises the risk of ventricular arrhythmia. The combination also has no sound therapeutic rationale, since they act on overlapping ribosomal targets.
How serious is the interaction between Erythromycin and Quinupristin / dalfopristin?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination if possible. If both are necessary, monitor ECG and electrolytes.
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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