Drug interactions
Erythromycin + Nirmatrelvir
Severity: Moderate
Erythromycin and Nirmatrelvir: 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
Nirmatrelvir is a CYP3A4 inhibitor and may increase erythromycin concentrations. This raises the risk of erythromycin adverse effects, including QT prolongation and torsades de pointes.
What this interaction means in plain words
Erythromycin and Nirmatrelvir 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.
Erythromycin belongs to Anti Bacterial; Nirmatrelvir belongs to Anti Virals.
Why it happens
Nirmatrelvir inhibits CYP3A4, decreasing erythromycin metabolism.
What to do
Consider an alternative antibiotic such as azithromycin if feasible. If coadministered, monitor for gastrointestinal effects and obtain an ECG in patients with QT risk factors.
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?
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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
Other interactions of Nirmatrelvir
- Alfuzosin + Nirmatrelvir Contraindicated
- Amiodarone + Nirmatrelvir Contraindicated
- Apalutamide + Nirmatrelvir Contraindicated
- Carbamazepine + Nirmatrelvir Contraindicated
- Colchicine + Nirmatrelvir Contraindicated
- Dronedarone + Nirmatrelvir Contraindicated
Frequently asked questions
Can I take Erythromycin with Nirmatrelvir?
MediHelp rates the interaction as moderate. Erythromycin and Nirmatrelvir 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. Nirmatrelvir is a CYP3A4 inhibitor and may increase erythromycin concentrations. This raises the risk of erythromycin adverse effects, including QT prolongation and torsades de pointes.
How serious is the interaction between Erythromycin and Nirmatrelvir?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Consider an alternative antibiotic such as azithromycin if feasible. If coadministered, monitor for gastrointestinal effects and obtain an ECG in patients with QT risk factors.
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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