Drug interactions
Crizotinib + Saquinavir
Severity: Contraindicated
Crizotinib and Saquinavir: 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
Both drugs prolong the QT interval and saquinavir is a strong CYP3A4 inhibitor that can raise crizotinib concentrations. Together they increase the risk of serious ventricular arrhythmias including torsades de pointes.
What this interaction means in plain words
Crizotinib and Saquinavir 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.
Why it happens
Additive QT prolongation with CYP3A4 inhibition by saquinavir increasing crizotinib exposure.
What to do
Avoid the combination and choose an antiretroviral not affecting QT or CYP3A4. If unavoidable, obtain baseline and serial ECGs and correct electrolytes.
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 Crizotinib
- Crizotinib + Flibanserin Contraindicated
- Crizotinib + Lomitapide Contraindicated
- Crizotinib + Lonafarnib Contraindicated
- Crizotinib + Pimozide Contraindicated
- Crizotinib + Thioridazine Contraindicated
- Adagrasib + Crizotinib Major
Frequently asked questions
Can I take Crizotinib with Saquinavir?
MediHelp rates the interaction as contraindicated. Crizotinib and Saquinavir 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. Both drugs prolong the QT interval and saquinavir is a strong CYP3A4 inhibitor that can raise crizotinib concentrations. Together they increase the risk of serious ventricular arrhythmias including torsades de pointes.
How serious is the interaction between Crizotinib and Saquinavir?
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 choose an antiretroviral not affecting QT or CYP3A4. If unavoidable, obtain baseline and serial ECGs and correct electrolytes.
What other medicines interact with Crizotinib?
MediHelp also lists interactions of Crizotinib with, for example, Flibanserin, Lomitapide, Lonafarnib. The full list is on the Crizotinib page.
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