Drug interactions
Primaquine + Procainamide
Severity: Major
Primaquine and Procainamide: major interaction.
Last updated Sources: US FDA label
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
Procainamide prolongs the QT interval and can cause torsades de pointes. Primaquine may add to this effect.
What this interaction means in plain words
Primaquine and Procainamide 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.
What to do
Avoid if possible and use an alternative antimalarial. If unavoidable, monitor the ECG and keep potassium and magnesium normal.
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 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 Procainamide?
MediHelp rates the interaction as major. Primaquine and Procainamide 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. Procainamide prolongs the QT interval and can cause torsades de pointes. Primaquine may add to this effect.
How serious is the interaction between Primaquine and Procainamide?
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 if possible and use an alternative antimalarial. If unavoidable, monitor the ECG and keep potassium and magnesium normal.
What other medicines interact with Primaquine?
MediHelp also lists interactions of Primaquine with, for example, Pimozide, Amiodarone, Amisulpride. The full list is on the Primaquine page.
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