Drug interactions
Dofetilide + Levofloxacin
Severity: Major
Dofetilide and Levofloxacin: major interaction.
Last updated Sources: EMA 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 is a potent QT-prolonging antiarrhythmic, and adding levofloxacin increases the risk of torsades de pointes. The consequences can be fatal ventricular arrhythmia.
What this interaction means in plain words
Dofetilide and Levofloxacin 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; Levofloxacin belongs to Anti Bacterial.
Why it happens
Additive hERG potassium channel blockade causing delayed repolarization.
What to do
Avoid the combination and choose an antibiotic without QT effects. If it cannot be avoided, use continuous ECG monitoring and keep electrolytes 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 Levofloxacin
- Dronedarone + Levofloxacin Contraindicated
- Ibutilide + Levofloxacin Contraindicated
- Levofloxacin + Thioridazine Contraindicated
- Levofloxacin + Vandetanib Contraindicated
- Levofloxacin + Ziprasidone Contraindicated
- Adagrasib + Levofloxacin Major
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 Levofloxacin?
MediHelp rates the interaction as major. Dofetilide and Levofloxacin 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 is a potent QT-prolonging antiarrhythmic, and adding levofloxacin increases the risk of torsades de pointes. The consequences can be fatal ventricular arrhythmia.
How serious is the interaction between Dofetilide and Levofloxacin?
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 and choose an antibiotic without QT effects. If it cannot be avoided, use continuous ECG monitoring and keep electrolytes normal.
What other medicines interact with Levofloxacin?
MediHelp also lists interactions of Levofloxacin with, for example, Dronedarone, Ibutilide, Thioridazine. The full list is on the Levofloxacin page.
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