Prescription medicine
Metolazone First approved as Zaroxolyn
Metolazone (Zaroxolyn) is a prescription medicine with an FDA approval on record since 1973. FDA's NDC Directory lists it from 19 generic labelers, and pharmacies paid $0.233 per metolazone 2.5 mg tablet in the October 7, 2026 NADAC survey.
- Generic listed
Check it at the source: the metolazone FDA label on DailyMed (effective December 11, 2025, Unichem Pharmaceuticals (USA), Inc.); the NDA 17386 record on Drugs@FDA; every metolazone label on DailyMed.
Highlights of the record
FDA label of December 11, 2025; NDC Directory, Drugs@FDA and Orange Book, October 8, 2026; NADAC October 7, 2026
Used for
From the label: indications and usageMetolazone tablets, USP, are indicated for the treatment of salt and water retention including: edema accompanying congestive heart failure;
Forms and strengths
- 2.5 mg
- 5 mg
- 10 mg
Tablet.
On the market
- Earliest approval on file
- November 27, 1973 Zaroxolyn, I3 Pharms; Drugs@FDA’s file, where older or withdrawn approvals can be missing
- Generic approvals
- 14 first December 19, 2003; 11 with a marketed status in Drugs@FDA
- Labelers listed (NDC)
- 19 of which 19 under generic applications, 0 under brand applications, repackagers included
Supply and safety
- Pharmacy cost (NADAC)
- $0.233 per tablet Metolazone 2.5 mg tablet
- Shortage (FDA)
- No current entry
- Recalls by its makers (FDA)
- No recall recorded
- FAERS reports
- 11,175 through July 30, 2026
What is metolazone used for?
From the label: indications and usageMetolazone tablets, USP, are indicated for the treatment of salt and water retention including: edema accompanying congestive heart failure; edema accompanying renal diseases, including the nephrotic syndrome and states of diminished renal function. Metolazone tablets, USP, are also indicated for the treatment of hypertension, alone or in combination with other antihypertensive drugs of a different class. MYKROX Tablets, a more rapidly available form of metolazone, are intended for the treatment of new patients with mild to moderate hypertension. A dose titration is necessary if MYKROX Tablets are to be substituted for metolazone tablets, USP, in the treatment of hypertension. […]
Conditions named in the indications of metolazone's FDA labels, with every medicine labeled for each:
From other metolazone labelsEdema (fluid retention): Metolazone tablets, USP, are indicated in pregnancy when edema is due to pathologic causes, just as it is in the absence of pregnancy (see PRECAUTIONS).
FDA pharmacologic class: Thiazide-like Diuretic.
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
Is there a generic for metolazone (Zaroxolyn)?
The FDA approved the first generic metolazone on December 19, 2003. 14 generic applications are approved; 11 of them carry a current (not discontinued) marketing status in Drugs@FDA; that status is not evidence that the generic is on sale.
FDA's NDC Directory lists metolazone from 19 labelers under a generic (ANDA) application. A listing means the company has registered the product for sale; it does not show that every pharmacy stocks it.
- 1973 earliest approval on file
- 2003 first generic approved
Source: Drugs@FDA, FDA NDC Directory and the Orange Book (openFDA bulk files, October 8, 2026)
What do pharmacies pay for metolazone (Zaroxolyn)?
In CMS's NADAC survey of October 7, 2026, pharmacies paid $0.233 per Metolazone 2.5 mg tablet, up 8% from $0.216 on October 8, 2025. The chart's scale runs from the lowest to the highest price shown, not from zero. NADAC is what retail pharmacies paid their wholesalers, per unit, in CMS's monthly survey; what a patient pays depends on insurance and the pharmacy.
- Metolazone 2.5 mg tablet (generic)
| Strength and form | Brand or generic | Pharmacy cost | 30 tablets, or one pen or vial | 12-month change |
|---|---|---|---|---|
| Metolazone 10 mg tablet | Generic | $0.381 per tablet | $11.44 | -12% |
| Metolazone 2.5 mg tablet | Generic | $0.233 per tablet | $6.98 | +8% |
| Metolazone 5 mg tablet | Generic | $0.239 per tablet | $7.18 | -16% |
Source: CMS National Average Drug Acquisition Cost (NADAC) survey, October 7, 2026: what retail pharmacies paid per unit; not a counter price
What does the metolazone label say about other medicines?
The metolazone label names 3 other medicines in its interaction, contraindication or warning sections. The sentences are the labels' own; a label lists what its studies and reports found, not every interaction.
| Medicine named | Section | What the label says |
|---|---|---|
| Furosemide | drug interactions | Drug 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). |
| Lithium | drug interactions | Lithium Serum lithium levels may increase (see WARNINGS). |
| Methenamine | drug interactions | Methenamine Efficacy may be decreased due to urinary alkalizing effect of metolazone. |
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
What do FAERS reports show for metolazone?
The FDA Adverse Event Reporting System holds 11,175 reports that list metolazone among the medicines taken, through July 30, 2026, each a report of something that happened, not proof the medicine caused it; 2,203 are coded as a death and 5,777 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is.
Reports received each year
The most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026
What else is labeled for the same conditions as metolazone?
79 other medicines are given the same way (oral) and in the same FDA class as metolazone or labeled mainly for the same use (high blood pressure), the same class first. High blood pressure lists all 88 medicines labeled for it, by any route. The first 8 are below. They are listed as records, not as substitutes: whether one can replace another is a prescriber's decision.
| Medicine | Shared indication | Generic labelers (oral) | Pharmacy cost | Shortage |
|---|---|---|---|---|
| Chlorthalidone | High blood pressure, Heart failure, Edema (fluid retention) | 36 labelers | $0.0743 per tablet 25 mg tablet | No current entry |
| Indapamide | High blood pressure, Heart failure, Edema (fluid retention) | 8 labelers | $0.109 per tablet 1.25 mg tablet | No current entry |
| Atenolol and chlorthalidone | High blood pressure | 10 labelers | $0.335 per unit 100-25 | No current entry |
| Amlodipine and indapamide and telmisartan | High blood pressure | none listed | n/a | No current entry |
| Azilsartan and chlorthalidone | High blood pressure | none listed | $8.49 per tablet 40-12.5 mg tablet | No current entry |
| Metoprolol | High blood pressure, Heart failure | 64 labelers | $0.085 per tablet 100 mg tablet | A presentation being discontinued |
| Diltiazem | High blood pressure | 42 labelers | $0.144 per capsule 24h ER(cd) 120 mg capsule | A presentation being discontinued |
| Lisinopril | High blood pressure, Heart failure | 36 labelers | $0.0254 per tablet 20 mg tablet | No current entry |
Every medicine labeled for the same conditions as metolazone
Source: FDA drug labels (indications), NDC Directory, NADAC of October 7, 2026, FDA shortages (October 8, 2026)
How does metolazone compare with medicines for the same use?
7 side-by-side pages set metolazone beside a medicine whose label shares a use: approvals, generics, pharmacy cost, warnings and supply.
What next?
- Alternatives to metolazone
- 79 medicines for the same use
- Other thiazide-like diuretics
- the pharmacologic class, with prices and generics
- Metolazone side effects
- the label's list beside FAERS reports
- Check an interaction
- what two or more labels say about each other