Drug interactions
Fluoxetine + Procainamide
Severity: Major
Fluoxetine 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. Fluoxetine adds QT liability and inhibits CYP2D6, which may increase procainamide levels.
What this interaction means in plain words
Fluoxetine 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, with possible CYP2D6 inhibition raising procainamide levels.
What to do
Avoid combining where an alternative is available. If both are needed, monitor ECG, QTc, electrolytes and procainamide and NAPA levels.
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 Fluoxetine
- Fluoxetine + Isocarboxazid Contraindicated
- Fluoxetine + Mavacamten Contraindicated
- Fluoxetine + Methylene blue Contraindicated
- Fluoxetine + Phenelzine Contraindicated
- Fluoxetine + Pimozide Contraindicated
- Fluoxetine + Rasagiline Contraindicated
Frequently asked questions
Can I take Fluoxetine with Procainamide?
MediHelp rates the interaction as major. Fluoxetine 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. Fluoxetine adds QT liability and inhibits CYP2D6, which may increase procainamide levels.
How serious is the interaction between Fluoxetine 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 combining where an alternative is available. If both are needed, monitor ECG, QTc, electrolytes and procainamide and NAPA levels.
What other medicines interact with Fluoxetine?
MediHelp also lists interactions of Fluoxetine with, for example, Isocarboxazid, Mavacamten, Methylene blue. The full list is on the Fluoxetine page.
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