Furosemide Injection and Metolazone: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Metolazone
No brand names on recordFurosemide Injection
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
Increased risk of electrolyte and fluid imbalance
Interaction Deep Dive
Concomitant use of metolazone and a loop diuretic may lead to unusually large or prolonged loss of fluid and electrolytes1. Closely monitor fluids and electrolytes status when these drugs are administered together.
Why it happens (mechanism)
Unknown
Common questions
Can I take Furosemide Injection and Metolazone together?
Increased risk of electrolyte and fluid imbalance Always confirm with your pharmacist or prescriber before making any change.
How serious is the Furosemide Injection and Metolazone 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 "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Furosemide Injection or Metolazone 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 (1)
- Product Information: metolazone oral tablets, metolazone oral tablets. Sandoz,Inc, Princeton, NJ, 2006. DailyMed
Keep reading about Metolazone
Keep reading about Furosemide Injection
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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