Drug interactions
Ribociclib + Saquinavir
Severity: Contraindicated
Ribociclib 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 boosted with ritonavir, a strong CYP3A4 inhibitor that raises ribociclib levels. The combination significantly raises the risk of torsades de pointes. Saquinavir labeling contraindicates use with other QT-prolonging drugs.
What this interaction means in plain words
Ribociclib 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 increasing ribociclib exposure.
What to do
Do not coadminister; choose an alternative antiretroviral or CDK4/6 inhibitor regimen.
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 Ribociclib
- Amiodarone + Ribociclib Contraindicated
- Cisapride + Ribociclib Contraindicated
- Dofetilide + Ribociclib Contraindicated
- Dronedarone + Ribociclib Contraindicated
- Flibanserin + Ribociclib Contraindicated
- Ibutilide + Ribociclib Contraindicated
Frequently asked questions
Can I take Ribociclib with Saquinavir?
MediHelp rates the interaction as contraindicated. Ribociclib 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 boosted with ritonavir, a strong CYP3A4 inhibitor that raises ribociclib levels. The combination significantly raises the risk of torsades de pointes. Saquinavir labeling contraindicates use with other QT-prolonging drugs.
How serious is the interaction between Ribociclib 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: Do not coadminister; choose an alternative antiretroviral or CDK4/6 inhibitor regimen.
What other medicines interact with Ribociclib?
MediHelp also lists interactions of Ribociclib with, for example, Amiodarone, Cisapride, Dofetilide. The full list is on the Ribociclib page.
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