Drug interactions
Quinidine + Selpercatinib
Severity: Major
Quinidine and Selpercatinib: 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 combined use raises the risk of torsades de pointes and other ventricular arrhythmias. The risk is greater with electrolyte disturbances, bradycardia or structural heart disease.
What this interaction means in plain words
Quinidine and Selpercatinib 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; Selpercatinib belongs to Oncology.
Why it happens
Additive pharmacodynamic prolongation of cardiac repolarization (QTc) by both drugs.
What to do
Avoid the combination if possible. If it is unavoidable, obtain a baseline and follow-up ECG, correct potassium and magnesium, and reduce or interrupt selpercatinib if QTc becomes markedly prolonged.
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 Selpercatinib
Frequently asked questions
Can I take Quinidine with Selpercatinib?
MediHelp rates the interaction as major. Quinidine and Selpercatinib 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 combined use raises the risk of torsades de pointes and other ventricular arrhythmias. The risk is greater with electrolyte disturbances, bradycardia or structural heart disease.
How serious is the interaction between Quinidine and Selpercatinib?
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 if possible. If it is unavoidable, obtain a baseline and follow-up ECG, correct potassium and magnesium, and reduce or interrupt selpercatinib if QTc becomes markedly prolonged.
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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