Drug interactions
Clarithromycin + Crizotinib
Severity: Major
Clarithromycin and Crizotinib: major interaction.
Last updated Sources: UK SmPC
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
Crizotinib is a CYP3A4 substrate and itself prolongs QT, and clarithromycin both raises crizotinib levels and adds QT risk. This can increase the chance of arrhythmia and other crizotinib toxicities.
What this interaction means in plain words
Clarithromycin and Crizotinib can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Clarithromycin belongs to Anti Bacterial; Crizotinib belongs to Oncology.
Why it happens
Additive QT prolongation combined with CYP3A4 inhibition increasing crizotinib exposure.
What to do
Avoid strong CYP3A4 inhibitors with crizotinib where possible. If needed, monitor ECG and electrolytes and reduce the crizotinib dose per labeling.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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References
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 Crizotinib
- Crizotinib + Flibanserin Contraindicated
- Crizotinib + Lomitapide Contraindicated
- Crizotinib + Lonafarnib Contraindicated
- Crizotinib + Pimozide Contraindicated
- Crizotinib + Saquinavir Contraindicated
- Crizotinib + Thioridazine Contraindicated
Frequently asked questions
Can I take Clarithromycin with Crizotinib?
MediHelp rates the interaction as major. Clarithromycin and Crizotinib can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Crizotinib is a CYP3A4 substrate and itself prolongs QT, and clarithromycin both raises crizotinib levels and adds QT risk. This can increase the chance of arrhythmia and other crizotinib toxicities.
How serious is the interaction between Clarithromycin and Crizotinib?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid strong CYP3A4 inhibitors with crizotinib where possible. If needed, monitor ECG and electrolytes and reduce the crizotinib dose per labeling.
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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