Drug interactions
Erythromycin + Larotrectinib
Severity: Moderate
Erythromycin and Larotrectinib: 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
Erythromycin may increase larotrectinib plasma concentrations because larotrectinib is a CYP3A4 substrate. This could increase toxicities such as neurotoxicity, transaminase elevation and myelosuppression.
What this interaction means in plain words
Erythromycin and Larotrectinib 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; Larotrectinib belongs to Oncology.
Why it happens
Erythromycin inhibits CYP3A4, reducing larotrectinib metabolism.
What to do
Where possible, choose an alternative antibiotic that does not inhibit CYP3A4. If coadministered, monitor for larotrectinib adverse effects and liver enzymes.
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 Larotrectinib
Frequently asked questions
Can I take Erythromycin with Larotrectinib?
MediHelp rates the interaction as moderate. Erythromycin and Larotrectinib 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 may increase larotrectinib plasma concentrations because larotrectinib is a CYP3A4 substrate. This could increase toxicities such as neurotoxicity, transaminase elevation and myelosuppression.
How serious is the interaction between Erythromycin and Larotrectinib?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Where possible, choose an alternative antibiotic that does not inhibit CYP3A4. If coadministered, monitor for larotrectinib adverse effects and liver enzymes.
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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