Drug interactions
Erythromycin + Osimertinib
Severity: Moderate
Erythromycin and Osimertinib: 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
Osimertinib is partly metabolized by CYP3A4, so erythromycin may modestly increase its exposure. Higher levels could add to toxicities such as QT prolongation, interstitial lung disease and cytopenias. Erythromycin itself also prolongs the QT interval.
What this interaction means in plain words
Erythromycin and Osimertinib 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; Osimertinib belongs to Oncology.
Why it happens
Erythromycin inhibits CYP3A4 metabolism of osimertinib, and both drugs have QT-prolonging potential.
What to do
Use a non-macrolide antibiotic where possible. If combined, obtain an ECG and electrolytes and monitor for osimertinib adverse effects.
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 Osimertinib
Frequently asked questions
Can I take Erythromycin with Osimertinib?
MediHelp rates the interaction as moderate. Erythromycin and Osimertinib 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. Osimertinib is partly metabolized by CYP3A4, so erythromycin may modestly increase its exposure. Higher levels could add to toxicities such as QT prolongation, interstitial lung disease and cytopenias. Erythromycin itself also prolongs the QT interval.
How serious is the interaction between Erythromycin and Osimertinib?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use a non-macrolide antibiotic where possible. If combined, obtain an ECG and electrolytes and monitor for osimertinib adverse effects.
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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