Drug interactions
Amiodarone + Quinidine
Severity: Major
Amiodarone 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 are class I/III antiarrhythmics that prolong the QT interval, and amiodarone also inhibits quinidine metabolism. The combination markedly raises the risk of torsades de pointes and quinidine toxicity.
What this interaction means in plain words
Amiodarone 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.
Amiodarone belongs to Cardiovascular; Quinidine belongs to Anti Parasitic.
Why it happens
Additive QT prolongation, with amiodarone inhibiting CYP3A4 and P-gp, raising quinidine levels.
What to do
Avoid unless specialist-supervised. If used, reduce the quinidine dose, monitor ECG and quinidine levels, and correct electrolytes.
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 Amiodarone
- Amiodarone + Amisulpride Contraindicated
- Amiodarone + Arsenic trioxide Contraindicated
- Amiodarone + Dofetilide Contraindicated
- Amiodarone + Dronedarone Contraindicated
- Amiodarone + Droperidol Contraindicated
- Amiodarone + Eliglustat Contraindicated
Frequently asked questions
Can I take Amiodarone with Quinidine?
MediHelp rates the interaction as major. Amiodarone 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 are class I/III antiarrhythmics that prolong the QT interval, and amiodarone also inhibits quinidine metabolism. The combination markedly raises the risk of torsades de pointes and quinidine toxicity.
How serious is the interaction between Amiodarone 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 unless specialist-supervised. If used, reduce the quinidine dose, monitor ECG and quinidine levels, and correct electrolytes.
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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