Methazolamide 50 mg Tablet, 100-count
🆔 Identity & classification
Where does this data come from?
🏷️ RxNorm drug class
This medicine belongs to the Carbonic anhydrase inhibitors class.
Where does this data come from?
🏭 Manufacturer & labeler
Where does this data come from?
🩺 Clinical
- 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?
Patient education
Supplement & herbal interactions
Some supplements/herbs that may interact with Methazolamide — tap one for details:
Methazolamide may be associated with lower levels of 7 nutrients — worth a chat with your pharmacist, not a cause for alarm.
Where does this data come from?
Ask a licensed pharmacist directly — free, answered by our team.
💊 What it looks like
Where does this data come from?
🧪 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.
💡 Tap an ingredient (hover on desktop) to see what it is and why it’s used.
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UNII O7TSZ97GEP
A mineral compound that serves as a filler and binding agent in tablets and capsules. It adds bulk to the medicine and helps hold ingredients together during manufacturing.
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Glyceryl dibehenate is a wax-like substance made from behenate fatty acids and glycerol. It functions as a binder and release-control agent in tablets and capsules, helping hold ingredients together and regulate how quickly the medicine dissolves and releases in your body.
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UNII U725QWY32X
Povidone K30 is a synthetic polymer made from petroleum. It acts as a binder to hold tablet ingredients together and as a disintegrant to help the tablet break apart in the stomach so the medicine can be absorbed.
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A starch-based powder made from potatoes and processed with sodium. It acts as a disintegrant, helping the tablet or capsule break apart quickly in the stomach so the medicine can be absorbed.
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UNII O8232NY3SJ
A plant-based carbohydrate derived from corn kernels. It acts as a filler to add bulk, a binder to hold ingredients together, and a disintegrant to help the tablet break apart in your stomach for absorption.
5 inactive ingredients listed in the exact product block matched to this NDC.
Where does this data come from?
ingredient classCode="IACT" elements from the exact product block matched by this NDC. Label-section narrative from DailyMed / the openFDA label index is shown separately when available.Inactive ingredient FAQ
Are inactive ingredients the same for every manufacturer?
Why might an inactive ingredient be missing?
Can inactive ingredients matter?
💲 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 system | Per ea | Per package |
|---|---|---|
| Retail pharmacies payNADAC · weekly | $1.468 | $146.84 / 100 tablets |
| Medicaid paysCMS SDUD · 12 mo | $1.59 | $158.90 / 100 tablets |
| Medicare drug plans payPart D · Q2 2026 | $1.59 | $159.26 / 100 tablets |
Where does this data come from?
🔁 Therapeutic equivalents
| Product | Labeler | Pack | NADAC/unit | TE | Status | Price 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 mgthis 72603-0167-01 | NorthStar | 100 tablets | $1.468 | AB | Availability likely | — |
| methazolamide 50 mg 00574-0791-01 | Padagis | 100 tablets | $1.507 | AB | Discontinued | +3% |
| 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 mg 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 | — |
Where does this data come from?
⏳ Availability & generic status
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?
🗺️ Medicaid utilization & spend
📊 Medicare Part D spend CMS · PART D · 2026 (Q1)
🔬 Reported adverse events (FAERS)
Top reported reactions
Age at onset
Reporter sex
Serious outcomes
Where does this data come from?
📦 Packaging — all sizes for this product
| Package NDC | Description | Marketing start | Status |
|---|---|---|---|
| 72603-0167-01 You're viewing this | 100 TABLET in 1 BOTTLE (72603-167-01) | 2023-08-30 | Active |
📄 Full prescribing information FDA SPL
🎯 Indications and Usage ▾
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 ▾
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 ▾
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 ▾
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 ▾
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 NorthStar Rx LLC at 1-800-206-7821 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
🔄 Drug Interactions ▾
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 ▾
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 ▾
Pediatric Use The safety and effectiveness of methazolamide in children have not been established.
🆘 Overdosage ▾
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 ▾
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 ▾
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 72603-166-01). 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 72603-167-01). 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 for: Northstar Rx LLC Memphis, TN 38141 Toll-free: 1-800-206-7821 Manufactured by: ANI Pharmaceuticals, Inc. Baudette, MN 56623 10680 Rev 07/23
📋 Description ▾
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 ▾
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.