Furosemide Injection and Formoterol: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Furosemide Injection
Formoterol
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
An increased risk of ECG changes or hypokalemia
Interaction Deep Dive
Use caution when coadministering formoterol with a non-potassium sparing diuretic as it may increase the risk of hypokalemia or ECG changes, especially with beta-agonist doses exceeding recommendations12.
Why it happens (mechanism)
Potentiation of diuretic-induced ECG changes and hypokalemia by formoterol
Common questions
Can I take Furosemide Injection and Formoterol together?
An increased risk of ECG changes or hypokalemia Always confirm with your pharmacist or prescriber before making any change.
How serious is the Furosemide Injection and Formoterol interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Furosemide Injection or Formoterol need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (2)
- Product Information: SYMBICORT AEROSPHERE® oral inhalation aerosol, budesonide formoterol fumarate oral inhalation aerosol. AstraZeneca Pharmaceuticals LP, Wilmington, DE, 2026.
- Product Information: BREZTRI AEROSPHERE® inhalation aerosol, budesonide, glycopyrrolate, formoterol fumarate inhalation aerosol. AstraZeneca Pharmaceuticals LP, Wilmington, DE, 2026. DailyMed
Keep reading about Furosemide Injection
Keep reading about Formoterol
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