Drug interactions
Flecainide + Primaquine
Severity: Major
Flecainide and Primaquine: 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
Flecainide slows cardiac conduction and can be proarrhythmic, and primaquine may add QT prolongation. The combination can raise the risk of serious ventricular arrhythmias, particularly in patients with structural heart disease.
What this interaction means in plain words
Flecainide and Primaquine 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.
Flecainide belongs to Cardiovascular; Primaquine belongs to Anti Parasitic.
Why it happens
Additive effects on cardiac conduction and repolarization, resulting in proarrhythmic risk.
What to do
Avoid the combination if possible, especially in structural heart disease. If needed, obtain a baseline and follow-up ECG 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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References
Other interactions of Primaquine
- Pimozide + Primaquine Contraindicated
- Amiodarone + Primaquine Major
- Amisulpride + Primaquine Major
- Anagrelide + Primaquine Major
- Arsenic trioxide + Primaquine Major
- Asenapine + Primaquine Major
Other interactions of Flecainide
- Flecainide + Nirmatrelvir Contraindicated
- Flecainide + Nirmatrelvir / ritonavir Contraindicated
- Flecainide + Pimozide Contraindicated
- Flecainide + Ritonavir Contraindicated
- Flecainide + Thioridazine Contraindicated
- Flecainide + Tipranavir Contraindicated
Frequently asked questions
Can I take Flecainide with Primaquine?
MediHelp rates the interaction as major. Flecainide and Primaquine 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. Flecainide slows cardiac conduction and can be proarrhythmic, and primaquine may add QT prolongation. The combination can raise the risk of serious ventricular arrhythmias, particularly in patients with structural heart disease.
How serious is the interaction between Flecainide and Primaquine?
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 if possible, especially in structural heart disease. If needed, obtain a baseline and follow-up ECG and correct electrolytes.
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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