HomeNDC LookupIngredientsMetolazone › 42571-0417-10
image loading
(from DailyMed)

Metolazone 5 mg Tablet, 1,000-count

by Micro Labs Limited · 1000 TABLET in 1 CONTAINER (42571-417-10)
NDC 42571-0417-10
🏷️ FDA NDC (as labeled) 42571-417-10 billing pads the product segment with a zero
This package
Contains1,000-count Pack sizes2 compare ↓
Also priced by: Part D plans $0.6266/unit — full pricing hub ↓
Also comes in: 100 tablets 42571-0417-01
Rx only Generic Discontinued Non-controlled ⚠ Discontinued by firm
🗂️ Data synced Jul 24, 2026 · sources: openFDA · FDA label (DailyMed) · FDA Orange & Purple Book · First Databank · CMS NADAC, ASP, Medicare & Medicaid · RxNorm
📋 All sources & update times →
⚠️
Excluded from the active FDA NDC Directory. The labeler reported this product as discontinued, so it is excluded from the active NDC Directory. The listing was last certified through Aug 2026. A label may still appear on DailyMed, but the NDC is no longer in the current FDA NDC Directory. Search the FDA NDC Directory ↗

🆔 Identity & classification

FDA NDC (as labeled) 42571-417-10
Product NDC 42571-417
11-digit billing NDC 42571041710
RxCUI 197978, 197979, 311671
UNII TZ7V40X7VX
UPC 0342571418014, 0342571416010, 0342571417017
Application # ANDA217563
SPL Set ID 9ab471a1-0f71-4452-ba57-518dcc6f9f18
Established class (EPC) Thiazide-like Diuretic
Physiologic effect Increased Diuresis
DEA schedule Non-controlled
Marketing category ANDA
Marketing status Discontinued
FDA listing status Discontinued by firm (certified through Aug 2026)
Marketing start 2025-03-01
Route ORAL
Dosage form TABLET
Substance METOLAZONE
TE code (Orange Book) AB · RLD · RS
Why two NDCs? The FDA registers this code as 42571-417-10 — a 5-3-2 layout, and that's what's printed on the package and shown on DailyMed. For insurance claims, every NDC is standardized to a uniform 11-digit 5-4-2 format by adding a zero to the product segment → 42571-0417-10. Same drug, same package — only the format differs.
Where does this data come from?
Identifiers from the FDA openFDA NDC Directory and Structured Product Labeling; RxCUI from RxNorm (NLM); GPI from Medi-Span; GCN / HIC / AHFS / legend from First Databank.

🏷️ RxNorm drug class

This medicine belongs to the Thiazide-like Diuretic class.

Pharmacologic class Thiazide-like Diuretic
Drug family (ATC) Sulfonamides, plain
Where does this data come from?
Therapeutic classes from RxNorm RxClass (U.S. National Library of Medicine) — Established Pharmacologic Class (FDA), ATC drug family (WHO) and mechanism of action, matched by this product’s RxCUI.

🏭 Manufacturer & labeler

LabelerMicro Labs Limited
Application holderMICRO LABS LTD
FDA applicationANDA217563 (ANDA)
Labeler code42571
First marketedMar 2025
Product typeHuman Prescription Drug
Portfolio190 products on file
The labeler markets the product; the application holder owns the FDA approval. They’re often the same company but can differ (e.g. a repackager or an authorized generic). A mailing address / phone appears here when the manufacturer includes it in the product’s FDA label (not all do).
Where does this data come from?
Labeler, application holder and registered establishment from the FDA openFDA NDC Directory and Drugs@FDA; address/contact from the product’s FDA label.

🩺 Clinical

📗 Our plain-language guide HelloPharmacist
  • Think of your kidneys as a filter. Normally, they reabsorb a lot of the sodium (salt) that passes through them. Metolazone blocks that process, so more sodium — and the water that...
  • What is metolazone actually doing in my body?
  • Because metolazone makes your kidneys flush out more than just water — it also causes you to lose potassium, sodium, and magnesium. If those levels drop too low, you can develop mu...
  • Why does my doctor keep checking my blood levels while I'm on this?
📖 Read our full Metolazone guide →
8
Nutrient depletion considerations

Metolazone may be associated with lower levels of 8 nutrients — worth a chat with your pharmacist, not a cause for alarm.

An association is not a deficiency. Educational only — don't start or stop anything without professional guidance.
Where does this data come from?
Plain-language summary from MedlinePlus (U.S. National Library of Medicine); supplement & herbal interactions and nutrient depletion data from the Natural Medicines database; our full guide is HelloPharmacist editorial content.

🧪 Inactive Ingredients / Excipients

Inactive ingredients, also called excipients, are components of the drug product other than the active ingredient. They may include fillers, dyes, coatings, preservatives, flavors, or other formulation ingredients.

We could not link this NDC to a current FDA Structured Product Label. An inactive-ingredient list is therefore not available from this source.
Where does this data come from?
Source: official FDA Structured Product Labeling (SPL) via DailyMed and the openFDA label index. Structured IACT rows and label-wide narrative are kept separate; availability and product-level specificity depend on the submitted label.

Inactive ingredient FAQ

Are inactive ingredients the same for every manufacturer?
No. Inactive ingredients can differ by manufacturer, dosage form, strength, and package / product version.
Why might an inactive ingredient be missing?
Some SPLs do not provide a complete structured inactive-ingredient list, and older or unusual labels may only include the information in narrative text.
Can inactive ingredients matter?
Yes. They can matter for allergies, intolerances, dyes, gluten / lactose concerns, preservatives, and formulation differences — but confirm with a pharmacist or the manufacturer when it’s clinically important.

💲 Pricing

A drug doesn't have one price. Each row is a different public payment system, and none is what you'd pay at the counter — that depends on your insurance. The ⓘ on each row explains what it measures.

Price systemPer eachPer package
Retail pharmacies payNADAC · weekly Not in the retail survey — common for institutional, discontinued, or low-volume packs.
Medicaid paysCMS SDUD · 12 mo No recent Medicaid claims on file for this NDC — rare and low-volume NDCs are suppressed in the public data.
Medicare drug plans payPart D · Q2 2026 $0.6266 $626.60 / 1000 tablets
Where does this data come from?
NADAC (National Average Drug Acquisition Cost) is the CMS weekly pharmacy-acquisition-cost survey — what pharmacies pay. ASP (Average Sales Price) is the CMS Medicare Part B drug-payment file, published quarterly. Medicaid pays is computed by us from CMS State Drug Utilization Data (total reimbursed ÷ units, trailing 12 months) — gross of rebates and inclusive of dispensing fees, so it reflects what Medicaid paid, not an acquisition cost. Medicare drug plans pay is the median negotiated point-of-sale unit cost across plans listing this NDC in the CMS quarterly Prescription Drug Plan pricing files, before rebates. The VA pays is the federal contract price (FSS, and the statutory Big 4 ceiling where listed) from the VA National Acquisition Center pharmaceutical price file. All are free public government data; each measures a different payer, so the figures are not directly comparable.

🔁 Therapeutic equivalents

ProductLabelerPackNADAC/unitTEStatusPrice vs. this
Metolazone 5 mg 00185-0055-01 Sandoz 100 tablets $0.264 AB Availability likely
Metolazone 5 mg 00378-6173-01 Mylan 100 tablets $0.264 AB Availability likely
Metolazone 5 mg 00904-7329-61 Major 100 tablets $0.264 AB Discontinued
Metolazone 5 mg 00904-7521-61 Major 100 tablets $0.264 AB Availability likely
Metolazone 5 mg 50742-0350-01 Ingenus 100 tablets $0.264 AB Availability likely
Metolazone 5 mg 51079-0024-20 Mylan 100 tablets $0.264 AB Availability likely
Metolazone 5 mg 58657-0741-01 Method 100 tablets $0.264 AB Availability likely
Metolazone 5 mg 58657-0941-01 Method 100 tablets $0.264 AB Availability likely
Metolazone 5 mg 60687-0635-01 American 100 tablets $0.264 AB Availability likely
Metolazone 5 mg 62332-0533-31 Alembic 100 tablets $0.264 AB Availability likely
Metolazone 5 mg 69292-0564-01 Amici 100 tablets $0.264 AB Availability likely
Metolazone 5 mg 72888-0053-01 Advagen 100 tablets $0.264 AB Availability likely
Metolazone 5 mg 76385-0137-01 Unichem 100 tablets $0.264 AB Availability likely
Metolazone 5 mg 10135-0766-01 Marlex 100 tablets AB FDA listed
Metolazone 5 mgthis 42571-0417-10 Micro 1000 tablets AB Discontinued
Metolazone 5 mg 43353-0931-09 Aphena 9000 tablets AB FDA listed
Metolazone 5 mg 46708-0533-31 Alembic 100 tablets AB FDA listed
Metolazone 5 mg 48433-0069-20 Safecor 100 tablets AB FDA listed
Metolazone 5 mg 51407-0432-01 Golden 100 tablets AB FDA listed
Metolazone 5 mg 63629-7875-01 Bryant 30 tablets AB FDA listed
Metolazone 5 mg 63629-8733-01 Bryant 100 tablets AB FDA listed
Metolazone 5 mg 71335-1944-01 Bryant 30 tablets AB FDA listed
Metolazone 5 mg 71335-2850-01 Bryant 100 tablets AB FDA listed
Metolazone 5 mg 72162-1050-01 Bryant 100 tablets AB FDA listed
Metolazone 5 mg 72162-2390-01 Bryant 100 tablets AB FDA listed
Metolazone 5 mg 81005-0125-01 Aarkish 100 tablets AB FDA listed
About this product: this is a generic version of the medicine. FDA equivalence ratings are shown when available, and other versions are listed above, least expensive first.
Where does this data come from?
Equivalents are other NDCs of the same ingredient, form and route from the openFDA NDC Directory, ranked least-expensive-first by NADAC. Therapeutic-equivalence (AB) ratings come from the FDA Orange Book; biologics use the FDA Purple Book for biosimilar & interchangeable status.

Availability & generic status

🏛️
2025
On the market since
Mar 2025
📍
2026
Currently FDA-listed
1 year listed
🔓
·
Generic on the market
this product is a generic
This is a generic drug

This product is an FDA-approved generic. Other versions of the same drug are listed under Therapeutic equivalents, least expensive first.

Where does this data come from?
Patents and exclusivity from the FDA Orange Book (small-molecule drugs), refreshed from public FDA data. Generic launch timing is an estimate, not a guarantee.

📊 Medicare Part D spend CMS · PART D · 2026 (Q1)

Medicare Part D (outpatient prescription) spending for Metolazone — the program that covers self-administered drugs. 10 manufacturers.
⚠️ Drug-level data: CMS publishes Part D spending by drug, not by NDC — these figures combine every manufacturer, strength and package size sold under the name Metolazone. That’s a different level of aggregation than the Medicaid card above, which is specific to this exact 11-digit NDC (pack size included), so the two aren’t directly comparable.
Period
Total Part D spend
$2.81M
Claims incl. refills
143.6K
Beneficiaries
90.5K
Spend / beneficiary
$31.03
Spend / claim
$19.56
Trend by period
💵 About the dollar figures: spending is what Part D plans paid before confidential manufacturer rebates, so the program’s real net cost is lower. A blank patient count means fewer than 11 people — CMS hides counts that small to protect privacy. Source: CMS Medicare Quarterly Part D Spending by Drug (data.cms.gov), updated quarterly.

🔬 Reported adverse events (FAERS)

Read carefully: FAERS reports are voluntary and unverified. Counts are not incidence, do not establish causation, are subject to reporting bias, and cannot be used to compare one drug to another. Shown for signal context only. Reports for METOLAZONE — the ingredient across all brands.

Top reported reactions

Dyspnoea1,247
Death879
Acute Kidney Injury799
Nausea761
Renal Failure716
Cardiac Failure Congestive683
Fatigue662

Reporter sex

11,176 reports
Male · 47%
Female · 53%
Unknown · 0%

Serious outcomes

Hospitalization5,777
Death2,204
Reports over time (by year) — tap or hover for the count & year
2019 2021 2023 2026 917 0
Most recent year is provisional (FAERS lags ~3 months).
Where does this data come from?
Adverse-event reports from the FDA Adverse Event Reporting System (FAERS) via openFDA. FAERS reports are voluntary and unverified — counts are not incidence and don’t establish causation.

📦 Packaging — all sizes for this product

Package NDCDescription Marketing startStatus
42571-0417-01 100 TABLET in 1 CONTAINER (42571-417-01) 2025-03-01 Discontinued by firm
42571-0417-10 You're viewing this 1000 TABLET in 1 CONTAINER (42571-417-10) 2025-03-01 Discontinued by firm

You're viewing the largest of 2 pack sizes for this product.

Pack size FAQ

What quantity is in NDC 42571-0417-10?
NDC 42571-0417-10 is a 1,000-count package — 1000 tablet in 1 container.
What is the difference between NDC 42571-0417-10 and NDC 42571-0417-01?
Both are Metolazone 5 mg Tablet — the drug itself is identical. NDC 42571-0417-10 is the 1,000-count package, while NDC 42571-0417-01 is the 100 tablets package.
What NDC number is used to bill for this package of Metolazone 5 mg Tablet?
Bill NDC 42571-0417-10 — the 11-digit billing format is 42571041710. Pharmacy and medical claims use the 11-digit form; the FDA label may print a shorter form of the same code.

🧭 About this NDC listing & data coverage

Finished prescription product No longer marketed (per FDA listing data)
What data is (and isn’t) available for this NDC — tap to expand
NDC identity (package / product / labeler codes) ✓ Available
Labeler ✓ Available
Product & package description ✓ Available
Marketing category & status ✓ Available
Active ingredient / dosage form / route ✓ Available
FDA label (SPL via DailyMed) ✓ Available
Package photos — Not published for this NDC No photo available yet for this listing.
Inactive ingredients (structured) — Not published for this NDC The labeler did not submit a structured excipient list, or no SPL is available.
NADAC pharmacy acquisition price (CMS) — Not published for this NDC CMS publishes NADAC only for NDCs reported in its retail-pharmacy survey.
Orange Book / therapeutic-equivalence data ✓ Available
HCPCS J-code billing crosswalk — Not published for this NDC Most self-administered / retail products have no J-code — that is normal.
Medicaid utilization (CMS SDUD) — Not published for this NDC CMS reports utilization only for NDCs with Medicaid claims above its privacy threshold.
“Not published” reflects what the public FDA / CMS / NLM sources provide for this exact package code — it is a property of the data feeds, not a judgment about the product.

Questions about this listing

Why is there no price listed?
The pricing shown on our NDC pages comes from CMS NADAC, a voluntary survey of retail community pharmacy invoices. CMS does not publish a NADAC for every NDC — packages outside the retail survey (institutional and hospital products, bulk packages, discontinued items, and many OTC items) may never receive one. A missing price reflects the survey's scope, not this product's actual cost, and does not mean the product is free or unavailable.
What does the discontinued status mean for this NDC?
The labeler reported a marketing end date (or the listing was delisted), so this specific package is no longer actively marketed. Remaining stock may still be dispensed for a time, and the NDC stays valid for historical records and claims — but data feeds (pricing, labeling) typically stop updating for it. Other package sizes or other manufacturers' versions of the same medication may still be marketed — see the equivalents section where available.
Is the NDC printed on the package the same as the 11-digit billing NDC?
Yes, they identify this exact package in different formats. The FDA registers it as 42571-417-10, which is what is printed on the packaging and shown on DailyMed. Insurance claims use a fixed 11-digit 5-4-2 format, so the short segment is padded with a leading zero: 42571-0417-10, written without dashes as 42571041710. The Identity section at the top of this page lists every form of this code.
What do the three segments of this NDC mean?
In 42571-0417-10, the first segment (42571) is the labeler code FDA assigned to Micro Labs Limited; the middle segment (0417) identifies this specific product — its ingredient, strength, and dosage form; and the last segment (10) identifies this exact package size and type. Together they name one specific package of one specific product.
Does this product come in other package sizes?
Yes — the FDA directory lists 1 other package presentation of this same product, including 100 tablets (42571-0417-01). Each has its own NDC and its own page — see the package list near the top of this page.
Who lists this product with the FDA?
Micro Labs Limited is the labeler of record for this NDC — the company under whose FDA-assigned code the package is listed. The labeler may be the manufacturer itself or a distributor marketing the product under its own code.
Do I need a prescription for this product?
This NDC is listed with FDA as a prescription product, so it is dispensed under a prescriber's order. Your pharmacist can tell you whether any over-the-counter forms of the same medication exist.
This page identifies an FDA-listed package (the NDC) and reports public regulatory and pricing data about the listing. It is reference information, not a medical recommendation — talk to your pharmacist or prescriber about your own medication.
Where does this data come from?
Listing facts (marketing category, packager status, marketing dates) from the FDA openFDA NDC Directory; label availability from DailyMed; pricing coverage from CMS NADAC; equivalence scope from the FDA Orange Book.

📄 Full prescribing information FDA SPL

The complete FDA label for this product — the official prescribing information, verbatim, section by section. Jump with a chip, search within the label, or expand everything.
🚨 Boxed Warning 62 words

DO NOT INTERCHANGE DO NOT INTERCHANGE METOLAZONE TABLETS, USP, ZAROXOLYN ® TABLETS, AND OTHER FORMULATIONS OF METOLAZONE THAT SHARE THEIR SLOW AND INCOMPLETE BIOAVAILABILITY AND ARE NOT THERAPEUTICALLY EQUIVALENT AT THE SAME DOSES TO MYKROX ® TABLETS, A MORE RAPIDLY AVAILABLE AND COMPLETELY BIOAVAILABLE METOLAZONE PRODUCT. FORMULATIONS BIOEQUIVALENT TO ZAROXOLYN AND FORMULATIONS BIOEQUIVALENT TO MYKROX SHOULD NOT BE INTERCHANGED FOR ONE ANOTHER.

🎯 Indications and Usage ~1 min read

INDICATIONS AND USAGE Metolazone tablets 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 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 in the treatment of hypertension. See package circular for MYKROX Tablets. Usage In Pregnancy The routine use of diuretics in an otherwise healthy woman is inappropriate and exposes mother and fetus to unnecessary hazard.

Diuretics do not prevent development of toxemia of pregnancy, and there is no evidence that they are useful in the treatment of developed toxemia. Edema during pregnancy may arise from pathologic causes or from the physiologic and mechanical consequences of pregnancy. Metolazone tablets are indicated in pregnancy when edema is due to pathologic causes, just as it is in the absence of pregnancy (see PRECAUTIONS ).

Dependent edema in pregnancy resulting from restriction of venous return by the expanded uterus is properly treated through elevation of the lower extremities and use of support hose; use of diuretics to lower intravascular volume in this case is illogical and unnecessary. There is hypervolemia during normal pregnancy which is harmful to neither the fetus nor the mother (in the absence of cardiovascular disease), but which is associated with edema, including generalized edema, in the majority of pregnant women. If this edema produces discomfort, increased recumbency will often provide relief.

In rare instances, this edema may cause extreme discomfort which is not relieved by rest. In these cases, a short course of diuretics may be appropriate.

⏱️ Dosage and Administration ~2 min read

DOSAGE AND ADMINISTRATION Effective dosage of metolazone tablets should be individualized according to indication and patient response. A single daily dose is recommended. Therapy with metolazone tablets 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 5 to 20 mg once daily. Edema of renal disease: Metolazone tablets 5 to 20 mg once daily.

Mild to moderate essential hypertension: Metolazone tablets 2.5 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 (0.5 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 responsiveness. A decision to change the daily dose should be based on the results of thorough clinical and laboratory evaluations. If antihypertensive drugs or diuretics are given concurrently with metolazone tablets more careful dosage adjustment may be necessary.

For patients who tend to experience paroxysmal nocturnal dyspnea, it may be advisable to employ a larger dose to ensure prolongation of diuresis and saluresis for a full 24-hour period. Treatment Of Hypertension The time interval required for the initial dosage regimen to show effect may vary from three or four days to three to six weeks in the treatment of elevated blood pressure. Doses should be adjusted at appropriate intervals to achieve maximum therapeutic effect.

Contraindications 12 words

CONTRAINDICATIONS Anuria, hepatic coma or precoma, known allergy or hypersensitivity to metolazone.

⚠️ Warnings ~1 min read

WARNINGS Rapid Onset Hyponatremia And/Or Hypokalemia Rarely, the rapid onset of severe hyponatremia and/or hypokalemia has been reported following initial doses of thiazide and non-thiazide diuretics. When symptoms consistent with severe electrolyte imbalance appear rapidly, drug should be discontinued and supportive measures should be initiated immediately. Parenteral electrolytes may be required.

Appropriateness of therapy with this class of drugs should be carefully reevaluated. Hypokalemia Hypokalemia may occur with consequent weakness, cramps, and cardiac dysrhythmias. Serum potassium should be determined at regular and appropriate intervals, and dose reduction, potassium supplementation or addition of a potassium-sparing diuretic instituted whenever indicated.

Hypokalemia is a particular hazard in patients who are digitalized or who have or have had a ventricular arrhythmia; dangerous or fatal arrhythmias may be precipitated. Hypokalemia is dose related. Concomitant Therapy Lithium In general, diuretics should not be given concomitantly with lithium because they reduce its renal clearance and add a high risk of lithium toxicity.

Read prescribing information for lithium preparations before use of such concomitant therapy. Furosemide Unusually large or prolonged losses of fluids and electrolytes may result when metolazone tablets are administered concomitantly to patients receiving furosemide (see PRECAUTIONS, Drug Interactions ). Other Antihypertensive Drugs When metolazone tablets are used with other antihypertensive drugs, particular care must be taken to avoid excessive reduction of blood pressure, especially during initial therapy.

Cross-Allergy Cross-allergy may occur when metolazone tablets are given to patients known to be allergic to sulfonamide-derived drugs, thiazides, or quinethazone. Sensitivity Reactions Sensitivity reactions (e.g., angioedema, bronchospasm) may occur with or without a history of allergy or bronchial asthma and may occur with the first dose of metolazone tablets.

🤒 Adverse Reactions ~1 min read

ADVERSE REACTIONS Metolazone tablets are usually well tolerated, and most reported adverse reactions have been mild and transient. Many of metolazone tablets 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. Metabolic Hypokalemia, hyponatremia, hyperuricemia, hypochloremia, hypochloremic alkalosis, hyperglycemia, glycosuria, increase in serum urea nitrogen (BUN) or creatinine, hypophosphatemia, hypomagnesemia, hypercalcemia. Musculoskeletal Joint pain, acute gouty attacks, muscle cramps or spasm.

Other Transient blurred vision, chills, dry mouth. In addition, adverse reactions reported with similar antihypertensive-diuretics, but which have not been reported to date for metolazone tablets include: bitter taste, sialadenitis, xanthopsia, respiratory distress (including pneumonitis), and anaphylactic reactions. These reactions should be considered as possible occurrences with clinical usage of metolazone tablets.

Whenever adverse reactions are moderate or severe, metolazone tablets dosage should be reduced or therapy withdrawn. To report SUSPECTED ADVERSE REACTIONS, contact Micro Labs USA, Inc. at 1-855-839-8195 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

🔄 Drug Interactions ~1 min read

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 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 three days before elective surgery. Salicylates And Other Non-Steroidal Anti-Inflammatory Drugs May decrease the antihypertensive effects of metolazone tablets. 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.

🔄 Drug / Laboratory Test Interactions 5 words

Drug/Laboratory Test Interactions None reported.

🤰 Pregnancy 154 words

Pregnancy Teratogenic Effects Reproduction studies performed in mice, rabbits, and rats treated during the appropriate period of gestation at doses up to 50 mg/kg/day have revealed no evidence of harm to the fetus due to metolazone. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, metolazone tablets should be used during pregnancy only if clearly needed.

Metolazone crosses the placental barrier and appears in cord blood. Non-Teratogenic Effects The use of metolazone tablets in pregnant women requires that the anticipated benefit be weighed against possible hazards to the fetus. These hazards include fetal or neonatal jaundice, thrombocytopenia, and possibly other adverse reactions which have occurred in the adult.

It is not known what effect the use of the drug during pregnancy has on the later growth, development, and functional maturation of the child. No such effects have been reported with metolazone.

🧒 Pediatric Use 208 words

Pediatric Use Safety and effectiveness in pediatric patients have not been established in controlled clinical trials. There is limited experience with the use of metolazone tablets in pediatric patients with congestive heart failure, hypertension, bronchopulmonary dysplasia, nephrotic syndrome and nephrogenic diabetes insipidus. Doses used generally ranged from 0.05 to 0.1 mg/kg administered once daily and usually resulted in a 1 to 2.8 kg weight loss and 150 to 300 cc increase in urine output.

Not all patients responded and some gained weight. Those patients who did respond did so in the first few days of treatment. Prolonged use (beyond a few days) was generally associated with no further beneficial effect or a return to baseline status and is not recommended.

There is limited experience with the combination of metolazone tablets and furosemide in pediatric patients with furosemide-resistant edema. Some benefited while others did not or had an exaggerated response with hypovolemia, tachycardia, and orthostatic hypotension requiring fluid replacement. Severe hypokalemia was reported and there was a tendency for diuresis to persist for up to 24 hours after metolazone tablets were discontinued.

Hyperbilirubinemia has been reported in 1 neonate. Close clinical and laboratory monitoring of all children treated with diuretics is indicated. See CONTRAINDICATIONS , WARNINGS , PRECAUTIONS .

🧓 Geriatric Use 139 words

Geriatric Use Clinical studies of metolazone tablets did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.

This drug is known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function.

🆘 Overdosage 160 words

OVERDOSAGE Intentional overdosage has been reported rarely with metolazone and similar diuretic drugs. Signs And Symptoms Orthostatic hypotension, dizziness, drowsiness, syncope, electrolyte abnormalities, hemoconcentration and hemodynamic changes due to plasma volume depletion may occur. In some instances depressed respiration may be observed.

At high doses, lethargy of varying degree may progress to coma within a few hours. The mechanism of CNS depression with thiazide overdosage is unknown. Also, GI irritation and hypermotility may occur.

Temporary elevation of BUN has been reported, especially in patients with impairment of renal function. Serum electrolyte changes and cardiovascular and renal function should be closely monitored. Treatment There is no specific antidote available but immediate evacuation of stomach contents is advised.

Dialysis is not likely to be effective. Care should be taken when evacuating the gastric contents to prevent aspiration, especially in the stuporous or comatose patient. Supportive measures should be initiated as required to maintain hydration, electrolyte balance, respiration, and cardiovascular and renal function.

🧬 Clinical Pharmacology ~1 min read

CLINICAL PHARMACOLOGY Metolazone is a quinazoline diuretic, with properties generally similar to the thiazide diuretics. The actions of metolazone result from interference with the renal tubular mechanism of electrolyte reabsorption. Metolazone acts primarily to inhibit sodium reabsorption at the cortical diluting site and to a lesser extent in the proximal convoluted tubule.

Sodium and chloride ions are excreted in approximately equivalent amounts. The increased delivery of sodium to the distal tubular exchange site results in increased potassium excretion. Metolazone does not inhibit carbonic anhydrase.

A proximal action of metolazone has been shown in humans by increased excretion of phosphate and magnesium ions and by a markedly increased fractional excretion of sodium in patients with severely compromised glomerular filtration. This action has been demonstrated in animals by micropuncture studies. When metolazone tablets are given, diuresis and saluresis usually begin within one hour and may persist for 24 hours or more.

For most patients, the duration of effect can be varied by adjusting the daily dose. High doses may prolong the effect. A single daily dose is recommended.

When a desired therapeutic effect has been obtained, it may be possible to reduce dosage to a lower maintenance level. The diuretic potency of metolazone tablets at maximum therapeutic dosage is approximately equal to thiazide diuretics. However, unlike thiazides, metolazone tablets may produce diuresis in patients with glomerular filtration rates below 20 mL/min.

Metolazone tablets and furosemide administered concurrently have produced marked diuresis in some patients where edema or ascites was refractory to treatment with maximum recommended doses of these or other diuretics administered alone. The mechanism of this interaction is unknown (see WARNINGS and PRECAUTIONS , Drug Interactions ). Maximum blood levels of metolazone are found approximately eight hours after dosing.

A small fraction of metolazone is metabolized. Most of the drug is excreted in the unconverted form in the urine.

📦 How Supplied / Storage and Handling 208 words

HOW SUPPLIED Metolazone tablets, USP, are biconvex, round tablets, and are available in three strengths: 2.5 mg – pink colored mottled tablets debossed with “M1” on one side and plain on other side, free from physical defects. It is available as follows: Bottles of 100 with child-resistant closure: NDC 42571-416-01 Bottles of 1000: NDC 42571-416-10 5 mg – blue colored mottled tablets debossed with “M2” on one side and plain on other side, free from physical defects. It is available as follows: Bottles of 100 with child-resistant closure: NDC 42571-417-01 Bottles of 1000: NDC 42571-417-10 10 mg – yellow colored tablets debossed with “M3” on one side and plain on other side, free from physical defects.

It is available as follows: Bottles of 100 with child-resistant closure: NDC 42571-418-01 Bottles of 1000: NDC 42571-418-10 Storage Store at 25°C (77°F); excursions permitted to 15° to 30°C (59° to 86°F) [see USP Controlled Room Temperature]. Protect from light. Keep out of the reach of children.

Dispense in a tight, light-resistant container as defined in the USP using a child-resistant closure. For more information about Metolazone Tablets, USP call 1-855-839-8195. All brand names are the trademarks of their respective owners.

Manufactured for: Micro Labs USA, Inc. Somerset, NJ 08873 Rev. 04/2023-01

📋 Description 117 words

DESCRIPTION Metolazone tablets, USP, for oral administration contain 2.5 mg, 5 mg, or 10 mg of metolazone, USP, a diuretic/saluretic/antihypertensive drug of the quinazoline class. Metolazone has the molecular formula C 16 H 16 ClN 3 O 3 S, the chemical name 7-chloro-1, 2, 3, 4-tetrahydro-2- methyl-3-(2-methylphenyl)-4-oxo-6-quinazolinesulfonamide, and a molecular weight of 365.83. The structural formula is: Metolazone is only sparingly soluble in water, but more soluble in plasma, blood, alkali, and organic solvents.

Inactive Ingredients: colloidal silicon dioxide, magnesium stearate, microcrystalline cellulose and dye: 2.5 mg - D&C Red No. 30 and FD&C Blue No. 1; 5 mg - FD&C Blue No.

2; 10 mg - D&C Yellow No. 10 and FD&C Yellow No. 6. metolazone-struc.jpg

💬 Information for Patients 29 words

Information For Patients Patients should be informed of possible adverse effects, advised to take the medication as directed, and promptly report any possible adverse reactions to the treating physician.

Source: FDA Structured Product Labeling, mirrored from DailyMed / openFDA. Prefer the government’s original formatting? View this label on DailyMed ↗
For educational and professional reference only — not medical advice. Pricing reflects published NADAC and CMS ASP (free public data) and may differ from your acquisition cost; always verify before billing or dispensing.