Drug interactions
Erythromycin + Lonafarnib
Severity: Contraindicated
Erythromycin and Lonafarnib: contraindicated 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
Lonafarnib is a sensitive CYP3A4 substrate, and erythromycin can greatly raise its concentrations, increasing toxicity such as gastrointestinal effects, QT prolongation and hepatic effects. Labeling contraindicates moderate and strong CYP3A inhibitors.
What this interaction means in plain words
Erythromycin and Lonafarnib are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two.
Erythromycin belongs to Anti Bacterial; Lonafarnib belongs to Miscellaneous.
Why it happens
Erythromycin inhibits CYP3A4-mediated metabolism of lonafarnib.
What to do
Avoid the combination and use a non-CYP3A-inhibiting antibiotic.
What to ask your pharmacist
- Is there an alternative to one of these two medicines for me?
- If both are essential, who is monitoring me and how often?
- Which symptoms mean I should stop and seek help straight away?
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References
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 Lonafarnib
- Alfuzosin + Lonafarnib Contraindicated
- Amobarbital + Lonafarnib Contraindicated
- Apalutamide + Lonafarnib Contraindicated
- Bosentan + Lonafarnib Contraindicated
- Carbamazepine + Lonafarnib Contraindicated
- Clarithromycin + Lonafarnib Contraindicated
Frequently asked questions
Can I take Erythromycin with Lonafarnib?
MediHelp rates the interaction as contraindicated. Erythromycin and Lonafarnib are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two. Lonafarnib is a sensitive CYP3A4 substrate, and erythromycin can greatly raise its concentrations, increasing toxicity such as gastrointestinal effects, QT prolongation and hepatic effects. Labeling contraindicates moderate and strong CYP3A inhibitors.
How serious is the interaction between Erythromycin and Lonafarnib?
MediHelp rates it contraindicated, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination and use a non-CYP3A-inhibiting antibiotic.
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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