Drug interactions
Fexinidazole + Quinidine
Severity: Major
Fexinidazole and Quinidine: 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 can prolong the QT interval, so giving them together raises the risk of torsades de pointes and other serious ventricular arrhythmias. Fexinidazole may also inhibit CYP3A4 and raise quinidine exposure, which would add to the arrhythmic risk.
What this interaction means in plain words
Fexinidazole and Quinidine 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.
Why it happens
Additive QT prolongation through potassium channel blockade, plus possible CYP3A4 inhibition by fexinidazole that reduces quinidine clearance.
What to do
Avoid the combination and choose an alternative antiarrhythmic if possible. If unavoidable, obtain a baseline and follow-up ECG, correct potassium and magnesium, and monitor quinidine levels.
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
Frequently asked questions
Can I take Fexinidazole with Quinidine?
MediHelp rates the interaction as major. Fexinidazole and Quinidine 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 can prolong the QT interval, so giving them together raises the risk of torsades de pointes and other serious ventricular arrhythmias. Fexinidazole may also inhibit CYP3A4 and raise quinidine exposure, which would add to the arrhythmic risk.
How serious is the interaction between Fexinidazole and Quinidine?
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 and choose an alternative antiarrhythmic if possible. If unavoidable, obtain a baseline and follow-up ECG, correct potassium and magnesium, and monitor quinidine levels.
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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