Metolazone: uses, dosing, side effects & brands
Metolazone is a thiazide-like diuretic sold in the U.S. under 2 brand and generic names, for edema, heart failure and hypertension. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.
Key facts
- Drug class
- Thiazide-Like Diuretic
- Treats
- Edema, Heart Failure and Hypertension
- Available as
- Tablet
- Sold as
- 2 products — Metolazone and Diulo
- Prescription?
- Prescription only
- Generic available?
- Yes
- What the pharmacy pays
- about $9 for a 30-count supply — not your price
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How metolazone is dosed
From the FDA label for Metolazone (application ANDA214799). Other metolazone products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
Effective dosage of metolazone tablets, USP, should be individualized according to indication and patient response. A single daily dose is recommended. Therapy with metolazone tablets, USP, should be titrated to gain an initial therapeutic response and to determine the minimal dose possible to maintain the desired therapeutic response. Usual Single Daily Dosage Schedules Suitable initial dosages will usually fall in the ranges given. Edema of cardiac failure: Metolazone tablets, USP, 5 to 20 mg once daily. Edema of renal disease: Metolazone tablets, USP, 5 to 20 mg once daily. Mild to moderate essential hypertension: Metolazone tablets, USP, 2½ to 5 mg once daily. New patients – MYKROX Tablets (metolazone tablets, USP) (see MYKROX package circular). If considered desirable to switch patients currently on metolazone tablets, USP, to MYKROX, the dose should be determined by titration starting at one tablet (½ mg) once daily and increasing to two tablets (1 mg) once daily if needed. Treatment Of Edematous States The time interval required for the initial dosage to produce an effect may vary. Diuresis and saluresis usually begin within one hour and persist for 24 hours or longer. When a desired therapeutic effect has been obtained, it may be advisable to reduce the dose if possible. The daily dose depends on the severity of the patient's condition, sodium intake, and…
Metolazone side effects
Metolazone tablets, USP, are usually well tolerated, and most reported adverse reactions have been mild and transient. Many of metolazone tablets, USP, related adverse reactions represent extensions of its expected pharmacologic activity and can be attributed to either its antihypertensive action or its renal/metabolic actions. The following adverse reactions have been reported. Several are single or comparably rare occurrences. Adverse reactions are listed in decreasing order of severity within body systems. Cardiovascular Chest pain/discomfort, orthostatic hypotension, excessive volume depletion, hemoconcentration, venous thrombosis, palpitations. Central And Peripheral Nervous System Syncope, neuropathy, vertigo, paresthesias, psychotic depression, impotence, dizziness/lightheadedness, drowsiness, fatigue, weakness, restlessness (sometimes resulting in insomnia), headache. Dermatologic/Hypersensitivity Toxic epidermal necrolysis (TEN), Stevens-Johnson Syndrome, necrotizing angiitis (cutaneous vasculitis), skin necrosis, purpura, petechiae, dermatitis (photosensitivity), urticaria, pruritus, skin rashes. Gastrointestinal Hepatitis, intrahepatic cholestatic jaundice, pancreatitis, vomiting, nausea, epigastric distress, diarrhea, constipation, anorexia, abdominal bloating, abdominal pain. Hematologic Aplastic/hypoplastic anemia, agranulocytosis, leukopenia, thrombocytopenia.…
Who shouldn’t take metolazone
Anuria, hepatic coma or precoma, known allergy or hypersensitivity to metolazone.
Metolazone 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). Other Antihypertensives When metolazone tablets, USP, are used with other antihypertensive drugs, care must be taken, especially during initial therapy. Dosage adjustments of other antihypertensives may be necessary. Alcohol, Barbiturates, And Narcotics The hypotensive effects of these drugs may be potentiated by the volume contraction that may be associated with metolazone therapy. Digitalis Glycosides Diuretic-induced hypokalemia can increase the sensitivity of the myocardium to digitalis. Serious arrhythmias can result. Corticosteroids Or ACTH May increase the risk of hypokalemia and increase salt and water retention. Lithium Serum lithium levels may increase (see WARNINGS). Curariform Drugs Diuretic-induced hypokalemia may enhance neuromuscular blocking effects of curariform drugs (such as tubocurarine) – the most serious effect would be respiratory depression which could proceed to apnea. Accordingly, it may be advisable to discontinue metolazone tablets, USP, three days before elective surgery. Salicylates And Other Non-Steroidal Anti-Inflammatory Drugs May decrease the antihypertensive effects of metolazone tablets USP. Sympathomimetics Metolazone may decrease arterial responsiveness to norepinephrine, but this diminution is not sufficient to preclude effectiveness of the pressor agent for therapeutic use. Insulin And Oral Antidiabetic Agents See Glucose Tolerance under PRECAUTIONS, General. Methenamine Efficacy may be decreased due to urinary alkalizing effect of metolazone. Anticoagulants Metolazone, as well as other thiazide-like diuretics, may affect the hypoprothrombinemic response to anticoagulants; dosage adjustments may be necessary.
Every metolazone product we track (2)
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
| # | Drug | Rating | Type | Form | Generic? | Pharmacy pays | |
|---|---|---|---|---|---|---|---|
| 1 | 72/100 | Prescription | Tablet | Generic | $9 | View → | |
| 2 | Not yet rated | Prescription | Tablet | Generic | $9 | View → |
What metolazone pills look like
Imprint codes, colour and shape from the FDA’s labelling data. Match the imprint on your pill — or search any imprint.
How long metolazone keeps
No metolazone label we read sets a separate limit for after opening, but they do specify how it must be stored — and the stability behind any date assumes those conditions.
Does metolazone expire? The in-use limits and storage rules from its labelsMetolazone and breastfeeding
From LactMed, the US National Library of Medicine’s Drugs and Lactation Database — quoted, not rewritten.
Full LactMed record for metolazone: levels in milk, effects in breastfed infants, and the drugs it would consider insteadNo information is available on the amount of metolazone in breastmilk. Intense diuresis with large doses may decrease breastmilk production. Other diuretics in low doses are preferred over metolazone.
National Institute of Child Health and Human Development, record revised July 15, 2024. LactMed states its information is not a substitute for professional judgement.
What people report to the FDA about metolazone
The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 11,263 reports naming metolazone, and the FDA flagged 80% of those reports as serious. The effects reported most often — leaving out reports about overdose, misuse or the condition being treated, which dominate the raw list for common medicines:
- dyspnoea1,240 reports
- acute kidney injury810 reports
- nausea765 reports
- renal failure727 reports
- cardiac failure congestive685 reports
- fatigue671 reports
- diarrhoea652 reports
- dizziness626 reports
Read these as a signal, not a rate. A report does not mean metolazone caused the effect — anyone can file one, and many describe people taking several medicines for several conditions. Crucially there is no denominator: FAERS does not record how many people took the drug, so these counts cannot be turned into “X% of patients” — a bigger number often just means a more widely used or more talked-about drug. Duplicates exist, and publicity drives reporting. For what is actually established, read the FDA label section above.
Source: openFDA drug/event (FAERS), retrieved July 25, 2026.
Related calculators
Frequently asked questions
What is metolazone?
Metolazone is a thiazide-like diuretic used to treat Edema, Heart Failure, Hypertension, Nephrotic Syndrome.
What kind of drug is metolazone?
The FDA classifies metolazone as a thiazide-like diuretic. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.
Can you take metolazone with other medicines?
It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run metolazone against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What brand names is metolazone sold under?
We track 2 metolazone-containing products in the U.S.: Metolazone and Diulo. They are the same active ingredient; they differ in form, manufacturer, price and FDA recall record.
What forms does metolazone come in?
Across the brands we track, metolazone is currently marketed as tablet, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.
Is there a generic metolazone?
Yes. Our catalog lists 1 generic metolazone product alongside the brand versions. A generic has the same active ingredient and must meet the FDA's bioequivalence standard; it usually costs less. Ask your pharmacist which one your plan covers.
Cite this page
- APA
- pharmaranks. (2026, July 24). Metolazone: uses, dosing, side effects & brands. https://pharmaranks.com/drugs/metolazone
- MLA
- “Metolazone: uses, dosing, side effects & brands.” pharmaranks, 24 July 2026, https://pharmaranks.com/drugs/metolazone.
We summarise public FDA and NIH sources — for a clinical claim, cite the primary source we link to as well.
Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.
Read the full FDA label for metolazone on DailyMed (NIH) ↗.