Drug interactions
Clarithromycin + Lonafarnib
Severity: Contraindicated
Clarithromycin and Lonafarnib: contraindicated 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
Lonafarnib is a sensitive CYP3A4 substrate and clarithromycin can greatly raise its levels, increasing the risk of toxicity including gastrointestinal effects, liver injury, and QT prolongation.
What this interaction means in plain words
Clarithromycin 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.
Clarithromycin belongs to Anti Bacterial; Lonafarnib belongs to Miscellaneous.
Why it happens
Clarithromycin inhibits CYP3A4, decreasing lonafarnib clearance.
What to do
Do not coadminister; use an alternative antibiotic, with ECG and liver function monitoring if exposure occurs.
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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Other interactions of Clarithromycin
- Astemizole + Clarithromycin Contraindicated
- Avanafil + Clarithromycin Contraindicated
- Cisapride + Clarithromycin Contraindicated
- Clarithromycin + Colchicine Contraindicated
- Clarithromycin + Conivaptan Contraindicated
- Clarithromycin + Dihydroergotamine Contraindicated
Other interactions of Lonafarnib
- Alfuzosin + Lonafarnib Contraindicated
- Amobarbital + Lonafarnib Contraindicated
- Apalutamide + Lonafarnib Contraindicated
- Bosentan + Lonafarnib Contraindicated
- Carbamazepine + Lonafarnib Contraindicated
- Crizotinib + Lonafarnib Contraindicated
Frequently asked questions
Can I take Clarithromycin with Lonafarnib?
MediHelp rates the interaction as contraindicated. Clarithromycin 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 clarithromycin can greatly raise its levels, increasing the risk of toxicity including gastrointestinal effects, liver injury, and QT prolongation.
How serious is the interaction between Clarithromycin 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: Do not coadminister; use an alternative antibiotic, with ECG and liver function monitoring if exposure occurs.
What other medicines interact with Clarithromycin?
MediHelp also lists interactions of Clarithromycin with, for example, Astemizole, Avanafil, Cisapride. The full list is on the Clarithromycin page.
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