Drug interactions
Dofetilide + Formoterol
Severity: Major
Dofetilide and Formoterol: 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
Dofetilide has a high risk of torsades de pointes, and formoterol may add to QT prolongation and lower potassium. Together the arrhythmic risk is meaningfully increased.
What this interaction means in plain words
Dofetilide and Formoterol 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; Formoterol belongs to Respiratory.
Why it happens
Additive QT prolongation, with beta-agonist-induced hypokalemia further increasing risk.
What to do
Avoid if possible; if formoterol is essential, maintain continuous monitoring as required for dofetilide, with ECG and electrolyte checks.
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 Formoterol
- Adagrasib + Formoterol Major
- Amiodarone + Formoterol Major
- Amisulpride + Formoterol Major
- Amitriptyline + Formoterol Major
- Amoxapine + Formoterol Major
- Arformoterol + Formoterol 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 Formoterol?
MediHelp rates the interaction as major. Dofetilide and Formoterol 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 has a high risk of torsades de pointes, and formoterol may add to QT prolongation and lower potassium. Together the arrhythmic risk is meaningfully increased.
How serious is the interaction between Dofetilide and Formoterol?
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 if possible; if formoterol is essential, maintain continuous monitoring as required for dofetilide, with ECG and electrolyte checks.
What other medicines interact with Formoterol?
MediHelp also lists interactions of Formoterol with, for example, Adagrasib, Amiodarone, Amisulpride. The full list is on the Formoterol page.
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