Drug interactions
Quinidine + Ribociclib
Severity: Major
Quinidine and Ribociclib: major 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, so giving them together raises the risk of torsades de pointes and sudden cardiac death. Quinidine may also raise ribociclib exposure through CYP3A4 and P-gp effects, further increasing the risk.
What this interaction means in plain words
Quinidine and Ribociclib 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.
Quinidine belongs to Anti Parasitic; Ribociclib belongs to Oncology.
Why it happens
Additive QT prolongation through cardiac potassium channel blockade, with possible increased ribociclib exposure.
What to do
Avoid the combination where possible and choose a non-QT-prolonging antiarrhythmic. If it cannot be avoided, obtain a baseline ECG, correct potassium and magnesium, and monitor the QTc closely.
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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Other interactions of Quinidine
- Adagrasib + Quinidine Contraindicated
- Arsenic trioxide + Quinidine Contraindicated
- Artemether / lumefantrine + Quinidine Contraindicated
- Chloroquine + Quinidine Contraindicated
- Dofetilide + Quinidine Contraindicated
- Dronedarone + Quinidine Contraindicated
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 Quinidine with Ribociclib?
MediHelp rates the interaction as major. Quinidine and Ribociclib 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. Both drugs prolong the QT interval, so giving them together raises the risk of torsades de pointes and sudden cardiac death. Quinidine may also raise ribociclib exposure through CYP3A4 and P-gp effects, further increasing the risk.
How serious is the interaction between Quinidine and Ribociclib?
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 the combination where possible and choose a non-QT-prolonging antiarrhythmic. If it cannot be avoided, obtain a baseline ECG, correct potassium and magnesium, and monitor the QTc closely.
What other medicines interact with Quinidine?
MediHelp also lists interactions of Quinidine with, for example, Adagrasib, Arsenic trioxide, Artemether / lumefantrine. The full list is on the Quinidine page.
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