Drug interactions
Encainide + Paroxetine
Severity: Major
Encainide and Paroxetine: 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
Encainide is metabolized by CYP2D6 to active metabolites, and paroxetine inhibits this enzyme. This shifts the balance of parent drug and metabolites and can change antiarrhythmic effect and proarrhythmic risk, as seen in poor metabolizers.
What this interaction means in plain words
Encainide and Paroxetine 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
Inhibition of CYP2D6-mediated metabolism of encainide to its active metabolites.
What to do
Avoid the combination if possible or monitor ECG (QRS and PR intervals) closely and adjust encainide dose. Consider an antidepressant that does not inhibit CYP2D6.
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 Paroxetine
- Isocarboxazid + Paroxetine Contraindicated
- Methylene blue + Paroxetine Contraindicated
- Paroxetine + Phenelzine Contraindicated
- Paroxetine + Pimozide Contraindicated
- Paroxetine + Procarbazine Contraindicated
- Paroxetine + Selegiline Contraindicated
Frequently asked questions
Can I take Encainide with Paroxetine?
MediHelp rates the interaction as major. Encainide and Paroxetine 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. Encainide is metabolized by CYP2D6 to active metabolites, and paroxetine inhibits this enzyme. This shifts the balance of parent drug and metabolites and can change antiarrhythmic effect and proarrhythmic risk, as seen in poor metabolizers.
How serious is the interaction between Encainide and Paroxetine?
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 or monitor ECG (QRS and PR intervals) closely and adjust encainide dose. Consider an antidepressant that does not inhibit CYP2D6.
What other medicines interact with Paroxetine?
MediHelp also lists interactions of Paroxetine with, for example, Isocarboxazid, Methylene blue, Phenelzine. The full list is on the Paroxetine page.
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