Drug interactions
Hydroxychloroquine + Quinidine
Severity: Major
Hydroxychloroquine 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
Quinidine strongly prolongs the QT interval and can cause torsades de pointes; hydroxychloroquine adds to this risk. Combined use may produce serious ventricular arrhythmias.
What this interaction means in plain words
Hydroxychloroquine 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.
Hydroxychloroquine belongs to Musculoskeletal; Quinidine belongs to Anti Parasitic.
Why it happens
Additive QT prolongation through potassium channel blockade.
What to do
Avoid the combination and choose an alternative agent. If it cannot be avoided, use continuous or serial ECG monitoring 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 Hydroxychloroquine
- Arsenic trioxide + Hydroxychloroquine Contraindicated
- Cisapride + Hydroxychloroquine Contraindicated
- Dronedarone + Hydroxychloroquine Contraindicated
- Hydroxychloroquine + Pimozide Contraindicated
- Hydroxychloroquine + Thioridazine Contraindicated
- Hydroxychloroquine + Vandetanib Contraindicated
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 Hydroxychloroquine with Quinidine?
MediHelp rates the interaction as major. Hydroxychloroquine 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. Quinidine strongly prolongs the QT interval and can cause torsades de pointes; hydroxychloroquine adds to this risk. Combined use may produce serious ventricular arrhythmias.
How serious is the interaction between Hydroxychloroquine 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 agent. If it cannot be avoided, use continuous or serial ECG monitoring and correct electrolytes.
What other medicines interact with Hydroxychloroquine?
MediHelp also lists interactions of Hydroxychloroquine with, for example, Arsenic trioxide, Cisapride, Dronedarone. The full list is on the Hydroxychloroquine page.
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