Drug interactions
Primaquine + Quinidine
Severity: Major
Primaquine and Quinidine: major interaction.
Last updated Sources: Base de donnees publique des medicaments (France)
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
Primaquine can prolong the QT interval, so combining it with quinidine increases the risk of torsades de pointes. Hemolysis risk from primaquine in G6PD deficiency is a separate concern.
What this interaction means in plain words
Primaquine 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.
Primaquine belongs to Anti Parasitic; Quinidine belongs to Anti Parasitic.
Why it happens
Additive pharmacodynamic QT prolongation.
What to do
Avoid the combination where possible, and monitor ECG and electrolytes if it is necessary.
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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References
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 Primaquine
- Pimozide + Primaquine Contraindicated
- Amiodarone + Primaquine Major
- Amisulpride + Primaquine Major
- Anagrelide + Primaquine Major
- Arsenic trioxide + Primaquine Major
- Asenapine + Primaquine Major
Frequently asked questions
Can I take Primaquine with Quinidine?
MediHelp rates the interaction as major. Primaquine 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. Primaquine can prolong the QT interval, so combining it with quinidine increases the risk of torsades de pointes. Hemolysis risk from primaquine in G6PD deficiency is a separate concern.
How serious is the interaction between Primaquine 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 where possible, and monitor ECG and electrolytes if it is necessary.
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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