What the FDA labels say about taking them together
Furosemide and metolazone
Metolazone's FDA label of December 11, 2025 names furosemide in its drug interactions section; the furosemide labels PlainMeds reads (4) do not name metolazone.
Check it at the source: the furosemide FDA label on DailyMed (effective September 30, 2025, Validus Pharmaceuticals LLC); the metolazone FDA label on DailyMed (effective December 11, 2025, Unichem Pharmaceuticals (USA), Inc.).
What does the furosemide label say about metolazone?
Furosemide's label (effective September 30, 2025) and its 3 other brand-application labels do not name metolazone in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Lasix), Validus Pharmaceuticals LLC, effective September 30, 2025 (SPL set 2c9b4d8f-0770-482d-a9e6-9c616a440b1a), via openFDA; the full label on DailyMed
What does the metolazone label say about furosemide?
Metolazone label, drug interactionsDrug Interactions Diuretics Furosemide and probably other loop diuretics given concomitantly with metolazone can cause unusually large or prolonged losses of fluid and electrolytes (see WARNINGS).
Metolazone label, warningsFurosemide Unusually large or prolonged losses of fluids and electrolytes may result when metolazone tablets, USP, are administered concomitantly to patients receiving furosemide (see PRECAUTIONS , Drug Interactions ).
Source: FDA drug label (Metolazone), Unichem Pharmaceuticals (USA), Inc., effective December 11, 2025 (SPL set c6fe5426-a184-44b8-a555-621d72aa5b9f), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Furosemide | Metolazone | |
|---|---|---|
| Labeled for | Heart failure, High blood pressure, Edema (fluid retention) | High blood pressure, Edema (fluid retention), Heart failure |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.490 per mL 20 mg/2 mL vial | $0.233 per tablet 2.5 mg tablet |
| Shortage now | In shortage | No current entry |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once