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Methazolamide 50 mg Tablet, 100-count — NDC 51407-0027-01 package photo

Methazolamide 50 mg Tablet, 100-count

by Golden State Medical Supply, Inc. · 100 TABLET in 1 BOTTLE (51407-027-01)
NDC 51407-0027-01
🏷️ FDA NDC (as labeled) 51407-027-01 billing pads the product segment with a zero
Rx only Generic On market Non-controlled
🗂️ 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 →

This page is curated, coded, and maintained by

Compiled from public FDA, CMS, DailyMed, NADAC, and related drug data sources. Editorial policy

🆔 Identity & classification

FDA NDC (as labeled) 51407-027-01
Product NDC 51407-027
11-digit billing NDC 51407002701
NCPDP billing unit EA — each (per item)
RxCUI 197939, 197940
UNII W733B0S9SD
Application # ANDA040001
SPL Set ID 723f830c-a534-55d1-e053-2a91aa0a403c
DEA schedule Non-controlled
Marketing category ANDA
Marketing status On market
FDA listing status Listed (active directory)
Marketing start 1993-06-30
Route ORAL
Dosage form TABLET
Substance METHAZOLAMIDE
GPI-14 37100030000305
GPI class methazolAMIDE
GCN Seq No 008169
GCN 34740
HICL code 003643
Ingredient (HICL) Methazolamide
HIC1 code R
Therapeutic class — broad (HIC1) Kidney/Urinary Tract
HIC2 code R1
Therapeutic class — intermediate (HIC2) Affect Primarily Kidneys/Urinary Tract
HIC3 code R1E
Therapeutic class — specific (HIC3) Carbonic Anhydrase Inhibitors
AHFS code 52:40.12.00
AHFS class Carbonic Anhydrase Inhibitors (52:40)
FDB label name METHAZOLAMIDE 50 MG TABLET
FDB brand name Methazolamide
Legend status F — Federal legend — prescription drug or device
TE code (Orange Book) AB · RLD · RS
Why two NDCs? The FDA registers this code as 51407-027-01 — 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 → 51407-0027-01. 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 Carbonic anhydrase inhibitors class.

Drug family (ATC) Carbonic anhydrase inhibitors
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

LabelerGolden State Medical Supply, Inc.
Application holderANI PHARMACEUTICALS INC
FDA applicationANDA040001 (ANDA)
Labeler code51407
First marketedJun 1993
Product typeHuman Prescription Drug
Portfolio671 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

Label name METHAZOLAMIDE 50 MG TABLET Ingredient Methazolamide
📗 Our plain-language guide HelloPharmacist
  • It's reducing the pressure inside your eye. Your eye constantly makes a fluid called aqueous humor, and methazolamide slows down how much of that fluid is produced. Less fluid mean...
  • What is methazolamide actually doing for my eyes?
  • The most common one people notice is a tingling or 'pins and needles' feeling in their hands and feet — it can be a little odd but it's well known with this type of drug. You might...
  • What side effects should I actually expect when I start taking it?
📖 Read our full Methazolamide guide →
7
Nutrient depletion considerations

Methazolamide may be associated with lower levels of 7 nutrients — worth a chat with your pharmacist, not a cause for alarm.

🧪 Full Methazolamide nutrient depletion report →
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.

Loading inactive ingredients from the official FDA label in the background. No external source is being called by this page request.
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 $1.59 $159.26 / 100 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
Methazolamide 50 mg 62559-0241-01 ANI 100 tablets $1.468 AB Availability likely —
Methazolamide 50 mg 68094-0808-50 Precision 100 tablets $1.468 AB Availability likely —
Methazolamide 50 mg 72603-0167-01 NorthStar 100 tablets $1.468 AB Availability likely —
methazolamide 50 mg 00574-0791-01 Padagis 100 tablets $1.507 AB Discontinued —
Methazolamide 50 mg 24208-0023-01 Bausch 1000 tablets — AB FDA listed —
Methazolamide 50 mg 27241-0247-01 Ajanta 100 tablets — AB FDA listed —
Methazolamide 50 mg 42571-0240-05 Micro 500 tablets — AB FDA listed —
Methazolamide 50 mgthis 51407-0027-01 Golden 100 tablets — AB FDA listed —
Methazolamide 50 mg 63629-1987-01 Bryant 100 tablets — AB FDA listed —
Methazolamide 50 mg 72162-1755-01 Bryant 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

🏛️
1993
On the market since
Jun 1993
📍
2026
Currently FDA-listed
33 years 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 Methazolamide — the program that covers self-administered drugs. 5 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 Methazolamide. 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
$2.31M
Claims incl. refills
11.6K
Beneficiaries
6.5K
Spend / beneficiary
$352.44
Spend / claim
$198.87
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 Methazolamide — the ingredient across all brands.

Top reported reactions

Fatigue41
Dizziness29
Dyspnoea28
Headache28
Blood Pressure Increased22
Asthenia21
Anxiety20

Age at onset

Adult28
Elderly31

Reporter sex

339 reports
Male · 44%
Female · 56%

Serious outcomes

Hospitalization89
Death28
Life-threatening9
Disabling8
Reports over time (by year) — tap or hover for the count & year
2019 2021 2023 2026 34 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
51407-0027-01 You're viewing this 100 TABLET in 1 BOTTLE (51407-027-01) 2018-01-01 Active

🧭 About this NDC listing & data coverage

Finished prescription product
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 ✓ Available
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.
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 51407-027-01, 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: 51407-0027-01, written without dashes as 51407002701. 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 51407-0027-01, the first segment (51407) is the labeler code FDA assigned to Golden State Medical Supply, Inc.; the middle segment (0027) identifies this specific product — its ingredient, strength, and dosage form; and the last segment (01) identifies this exact package size and type. Together they name one specific package of one specific product.
Is this package still being marketed?
Yes, per the latest FDA NDC Directory data on this page: this package is listed as actively marketed, with no marketing end date reported by Golden State Medical Supply, Inc.. Listing status can change — the directory data on this page refreshes weekly.
Who lists this product with the FDA?
Golden State Medical Supply, Inc. 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.
🎯 Indications and Usage ⏱️ Dosage and Administration ⛔ Contraindications ⚠️ Warnings 🤒 Adverse Reactions 🔄 Drug Interactions 🤰 Pregnancy 🧒 Pediatric Use 🆘 Overdosage 🧬 Clinical Pharmacology 📦 How Supplied / Storage and Handling 📋 Description 💬 Information for Patients
🎯 Indications and Usage 46 words ▾

INDICATIONS AND USAGE Methazolamide Tablets are indicated in the treatment of ocular conditions where lowering intraocular pressure is likely to be of therapeutic benefit, such as chronic open-angle glaucoma, secondary glaucoma, and preoperatively in acute angle-closure glaucoma where lowering the intraocular pressure is desired before surgery.

⏱️ Dosage and Administration 31 words ▾

DOSAGE AND ADMINISTRATION The effective therapeutic dose administered varies from 50 mg to 100 mg two or three times daily. The drug may be used concomitantly with miotic and osmotic agents.

⛔ Contraindications 71 words ▾

CONTRAINDICATIONS Methazolamide therapy is contraindicated in situations in which sodium and/or potassium serum levels are depressed, in cases of marked kidney or liver disease or dysfunction, in adrenal gland failure, and in hyperchloremic acidosis. In patients with cirrhosis, use may precipitate the development of hepatic encephalopathy. Long-term administration of methazolamide is contraindicated in patients with angle-closure glaucoma, since organic closure of the angle may occur in spite of lowered intraocular pressure.

⚠️ Warnings 89 words ▾

WARNINGS Fatalities have occurred, although rarely, due to severe reactions to sulfonamides including Stevens-Johnson syndrome, toxic epidermal necrolysis, fulminant hepatic necrosis, agranulocytosis, aplastic anemia, and other blood dyscrasias. Hypersensitivity reactions may recur when a sulfonamide is readministered, irrespective of the route of administration. If hypersensitivity or other serious reactions occur, the use of this drug should be discontinued.

Caution is advised for patients receiving high-dose aspirin and methazolamide concomitantly, as anorexia, tachypnea, lethargy, coma, and death have been reported with concomitant use of high-dose aspirin and carbonic anhydrase inhibitors.

🤒 Adverse Reactions 150 words ▾

ADVERSE REACTIONS Adverse reactions, occurring most often early in therapy, include paresthesias, particularly a “tingling” feeling in the extremities; hearing dysfunction or tinnitus; fatigue; malaise; loss of appetite; taste alteration; gastrointestinal disturbances such as nausea, vomiting, and diarrhea; polyuria; and occasional instances of drowsiness and confusion. Metabolic acidosis and electrolyte imbalance may occur. Transient myopia has been reported.

This condition invariably subsides upon diminution or discontinuance of the medication. Other occasional adverse reactions include urticaria, melena, hematuria, glycosuria, hepatic insufficiency, flaccid paralysis, photosensitivity, convulsions, and, rarely, crystalluria and renal calculi. Also see PRECAUTIONS: Information for Patients for possible reactions common to sulfonamide derivatives.

Fatalities have occurred, although rarely, due to severe reactions to sulfonamides including Stevens-Johnson syndrome, toxic epidermal necrolysis, fulminant hepatic necrosis, agranulocytosis, aplastic anemia, and other blood dyscrasias (see WARNINGS ). To report SUSPECTED ADVERSE REACTIONS, contact ANI Pharmaceuticals, Inc. at 1-855-204-1431 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

🔄 Drug Interactions 54 words ▾

Drug Interactions Methazolamide should be used with caution in patients on steroid therapy because of the potential for developing hypokalemia. Caution is advised for patients receiving high-dose aspirin and methazolamide concomitantly, as anorexia, tachypnea, lethargy, coma and death have been reported with concomitant use of high-dose aspirin and carbonic anhydrase inhibitors (see WARNINGS ).

🤰 Pregnancy 53 words ▾

Pregnancy Teratogenic effects Methazolamide has been shown to be teratogenic (skeletal anomalies) in rats when given in doses approximately 40 times the human dose. There are no adequate and well controlled studies in pregnant women. Methazolamide should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

🧒 Pediatric Use 14 words ▾

Pediatric Use The safety and effectiveness of methazolamide in children have not been established.

🆘 Overdosage 85 words ▾

OVERDOSAGE No data are available regarding methazolamide overdosage in humans as no cases of acute poisoning with this drug have been reported. Animal data suggest that even a high dose of methazolamide is nontoxic. No specific antidote is known.

Treatment should be symptomatic and supportive. Electrolyte imbalance, development of an acidotic state, and central nervous system effects might be expected to occur. Serum electrolyte levels (particularly potassium) and blood pH levels should be monitored.

Supportive measures may be required to restore electrolyte and pH balance.

🧬 Clinical Pharmacology ~2 min read ▾

CLINICAL PHARMACOLOGY Methazolamide is a potent inhibitor of carbonic anhydrase. Methazolamide is well absorbed from the gastrointestinal tract. Peak plasma concentrations are observed 1 to 2 hours after dosing.

In a multiple-dose, pharmacokinetic study, administration of methazolamide 25 mg bid, 50 mg bid, and 100 mg bid demonstrated a linear relationship between plasma methazolamide levels and methazolamide dose. Peak plasma concentrations (C max ) for the 25 mg, 50 mg and 100 mg bid regimens were 2.5 mcg/mL, 5.1 mcg/mL, and 10.7 mcg/mL, respectively. The area under the plasma concentration-time curves (AUC) was 1130 mcg.min/mL, 2571 mcg.min/mL, and 5418 mcg.min/mL for the 25 mg, 50 mg, and 100 mg dosage regimens, respectively.

Methazolamide is distributed throughout the body including the plasma, cerebrospinal fluid, aqueous humor of the eye, red blood cells, bile and extra-cellular fluid. The mean apparent volume of distribution (V area /F) ranges from 17 L to 23 L. Approximately 55% is bound to plasma proteins.

The steady-state methazolamide red blood cell:plasma ratio varies with dose and was found to be 27:1, 16:1, and 10:1 following the administration of methazolamide 25 mg bid, 50 mg bid, and 100 mg bid, respectively. The mean steady-state plasma elimination half-life for methazolamide is approximately 14 hours. At steady-state, approximately 25% of the dose is recovered unchanged in the urine over the dosing interval.

Renal clearance accounts for 20% to 25% of the total clearance of drug. After repeated bid-tid dosing, methazolamide accumulates to steady-state concentrations in 7 days. Methazolamide’s inhibitory action on carbonic anhydrase decreases the secretion of aqueous humor and results in a decrease in intraocular pressure.

The onset of the decrease in intraocular pressure generally occurs within 2 to 4 hours, has a peak effect in 6 to 8 hours and a total duration of 10 to 18 hours. Methazolamide is a sulfonamide derivative; however, it does not have any clinically significant antimicrobial properties. Although methazolamide achieves a high concentration in the cerebrospinal fluid, it is not considered an effective anticonvulsant.

Methazolamide has a weak and transient diuretic effect; therefore, use results in an increase in urinary volume, with excretion of sodium, potassium, and chloride. The drug should not be used as a diuretic. Inhibition of renal bicarbonate reabsorption produces an alkaline urine.

Plasma bicarbonate decreases, and a relative, transient metabolic acidosis may occur due to a disequilibrium in carbon dioxide transport in the red blood cell. Urinary citrate excretion is decreased by approximately 40% after doses of 100 mg every 8 hours. Uric acid output has been shown to decrease 36% in the first 24 hour period.

📦 How Supplied / Storage and Handling 110 words ▾

HOW SUPPLIED Methazolamide Tablets USP, 25 mg, are white, square, un-scored tablets, debossed “ANI” on one side and “240” on the other side; supplied in bottles of 100 (NDC 51407-026-01). Methazolamide Tablets USP, 50 mg, are white, round tablets, scored on one side and debossed “ANI” and “241” on the other side; supplied in bottles of 100 (NDC 51407-027-01). Store at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature].

Dispense in a tight container as defined in the USP, with a child-resistant closure (as required). Rx only Manufactured by: ANI Pharmaceuticals, Inc. Baudette, MN 56623 9656 Rev 05/25 Marketed by: GSMS, Inc.

Camarillo, CA 93012 USA ani

📋 Description 86 words ▾

DESCRIPTION Methazolamide, a sulfonamide derivative, is a white crystalline powder, weakly acidic, slightly soluble in water, alcohol and acetone. The chemical name for methazolamide is: N-[5-(aminosulfonyl)-3-methyl-1,3,4-thiadiazo1-2(3H)-ylidene]-acetamide and it has the following structural formula: Molecular Formula: C 5 H 8 N 4 O 3 S 2 Molecular Weight: 236.26 Each tablet, for oral administration, contains 25 mg or 50 mg of methazolamide USP. In addition, each tablet contains the following inactive ingredients: dibasic calcium phosphate dihydrate, glyceryl behenate, povidone, pregelatinized starch, and sodium starch glycolate. chemical structure

💬 Information for Patients 67 words ▾

Information for Patients Adverse reactions common to all sulfonamide derivatives may occur: anaphylaxis, fever, rash (including erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis), crystalluria, renal calculus, bone marrow depression, thrombocytopenic purpura, hemolytic anemia, leukopenia, pancytopenia, and agranulocytosis. Precaution is advised for early detection of such reactions, and the drug should be discontinued and appropriate therapy instituted. Caution is advised for patients receiving high-dose aspirin and methazolamide concomitantly.

Source: FDA Structured Product Labeling, mirrored from DailyMed / openFDA. Prefer the government’s original formatting? View this label on DailyMed ↗
← 51407-0026-01 · Golden 51407-0039-01 · Golden →
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.