Drug interactions
Dofetilide + Paroxetine
Severity: Major
Dofetilide and Paroxetine: major interaction.
Last updated Sources: UK SmPC
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
Dofetilide strongly prolongs the QT interval and carries a risk of torsades de pointes. Paroxetine has a small QT effect and can raise dofetilide exposure through limited interference with renal handling or metabolism, so the combination may add to arrhythmia risk.
What this interaction means in plain words
Dofetilide 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.
Dofetilide belongs to Cardiovascular; Paroxetine belongs to Central Nervous System.
Why it happens
Additive QT prolongation through potassium channel effects, with possible small pharmacokinetic increase in dofetilide exposure.
What to do
Prefer an antidepressant with lower QT liability when dofetilide is used. If combined, obtain a baseline ECG, monitor QTc 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
- Paroxetine 10 mg Tablets - SmPC sections 4.3/4.5 (class statement: drugs which prolong the QTc interval; "The risk of QTc prolongation and/or ventricular arrhythmias (e.g. TdP) may be increased with concomitant use of other drugs which prolong the QTc interval (e.g.") — electronic medicines compendium (UK SmPC)
Other interactions of Paroxetine
- Isocarboxazid + Paroxetine Contraindicated
- Methylene blue + Paroxetine Contraindicated
- Paroxetine + Phenelzine Contraindicated
- Paroxetine + Pimozide Contraindicated
- Paroxetine + Procarbazine Contraindicated
- Paroxetine + Selegiline Contraindicated
Other interactions of Dofetilide
- Amiodarone + Dofetilide Contraindicated
- Amisulpride + Dofetilide Contraindicated
- Amlodipine-hydrochlorothiazide-valsartan + Dofetilide Contraindicated
- Amlodipine-olmesartan-hydrochlorothiazide + Dofetilide Contraindicated
- Candesartan-hydrochlorothiazide + Dofetilide Contraindicated
- Captopril-hydrochlorothiazide + Dofetilide Contraindicated
Frequently asked questions
Can I take Dofetilide with Paroxetine?
MediHelp rates the interaction as major. Dofetilide 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. Dofetilide strongly prolongs the QT interval and carries a risk of torsades de pointes. Paroxetine has a small QT effect and can raise dofetilide exposure through limited interference with renal handling or metabolism, so the combination may add to arrhythmia risk.
How serious is the interaction between Dofetilide 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: Prefer an antidepressant with lower QT liability when dofetilide is used. If combined, obtain a baseline ECG, monitor QTc and keep potassium and magnesium normal.
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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