24 . January , 2019 - Thursday
Check todays hot topics or new products

Find a Drug: Advanced

Please Sign in or Register

All about: Methazolamide

Big Image Pronouncation: (meth-ah-ZOLE-ah-mide)
Class: Carbonic anhydrase inhibitor

Trade Names:
- Tablets 25 mg
- Tablets 50 mg

Mechanism of Action


Inhibits carbonic anhydrase enzyme, reducing rate of aqueous humor secretion and, thus, lowering IOP.



Well absorbed from the GI tract, reaching peak plasma levels in 1 to 2 h. The C max for the 25, 50, and 100 mg twice daily dosing regiments are 2.5, 5.1, and 10.7 mcg/mL, respectively. The AUCs are 1,130, 2,571, and 5,418 mcg•min/mL, respectively.


Methazolamide is distributed throughout the body including plasma, cerebrospinal fluid, aqueous humor, RBC, bile, and extracellular fluid. The Vd ranges from 17 to 23 L. Approximately 55% is bound to plasma proteins.


Mean steady-state plasma elimination t ½ is about 14 h. Approximately 25% is recovered unchanged in the urine over the dosing interval and renal Cl accounts for 20% to 25% of the total Cl.


Decrease in IOP usually occurs in 2 to 4 h.


About 6 to 8 h.


About 10 to 18 h.

Indications and Usage

Treatment of ocular conditions where lowering IOP is likely to be of therapeutic benefit (eg, chronic open-angle glaucoma, secondary glaucoma, preoperatively in acute angle-closure glaucoma).


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 (may precipitate hepatic encephalopathy); long-term administration in patients with angle-closure glaucoma.

Dosage and Administration


PO 50 to 100 mg twice daily or 3 times daily.

Drug Interactions

Aspirin (high-dose)

Anorexia, tachypnea, lethargy, coma, and death have been reported.


Use with caution because of risk of developing hypokalemia.

Laboratory Test Interactions

None well documented.

Adverse Reactions


Paresthesias; malaise; drowsiness; confusion; loss of appetite; convulsions.


Urticaria; Stevens-Johnson syndrome; toxic epidermal necrolysis.


Hearing dysfunction; tinnitus; transient myopia.


Electrolyte imbalance.


Taste alteration; GI disturbance (including nausea, vomiting, diarrhea); melena.


Polyuria; hematuria; glucosuria; crystalluria; renal calculi.


Agranulocytosis; aplastic anemia; other blood dyscrasias.


Hepatic insufficiency; fulminant hepatic necrosis.


Metabolic acidosis.


Flaccid paralysis.





Category C .




Safety and efficacy not established.


Patients with known sulfonamide sensitivity may show allergic reactions to methazolamide.

Hepatic Function

Use could precipitate hepatic coma.

Pulmonary conditions

Use in pulmonary obstruction and emphysema may aggravate or precipitate acidosis.

Recent Drug Updates at DrugIndexOnline:

Acetaminophen/Caffeine/Phenyltoloxamine Acetaminophen/Caffeine/Phenyltoloxamine
Generic Name: Acetaminophen/Caffeine/Phenyltoloxamine (ah-seet-ah-MIN-oh-fen/ka-FEEN/fen-ill-tole-OX-a-meen) Brand Name: FlextraAcetaminophen/Caffeine/Phenyltoloxamine is used for:Treating mild to moderate aches and pains associated with headache, muscle and joint soreness, backache, menstrual more...

Charcodote Charcodote
Some commonly used brand names are: In the U.S.— Actidose-Aqua 1 Actidose with Sorbitol 2 CharcoAid 2 CharcoAid G 1 CharcoAid 2000 1 Insta-Char in an Aqueous Base 1 Insta-Char in an Aqueous Base with Cherry Flavor 1 Insta-Char Pediatric in an Aqueous Base with Cherry Flavor 1 Insta-Char P more...

Clopidogrel Clopidogrel
Some commonly used brand names are: In the U.S.— Plavix Category Antithrombotic platelet aggregation inhibitor Description Clopidogrel (kloh-PID-oh-grel) is used to lessen the chance of heart attack or stroke. It is given to people who have already had a heart attack or stroke or more...

Halobetasol Cream Halobetasol Cream
Generic Name: Halobetasol Cream and Ointment (hal-oh-BAY-ta-sol) Brand Name: UltravateHalobetasol Cream is used for:Reducing itching and inflammation associated with different skin conditions. Halobetasol Cream is a super-high potency corticosteroid. It works by blocking the production of certai more...

Leuprolide Leuprolide
Generic Name: Leuprolide acetate Dosage Form: Injection Leuprolide Description Leuprolide Acetate Injection is a synthetic nonapeptide analog of naturally occurring gonadotropin releasing hormone (GnRH or LH-RH). The analog possesses greater more...

Mutamycin Mutamycin
Some commonly used brand names are: In the U.S.— Mutamycin In Canada— Mutamycin Category Antineoplastic Description Mitomycin (mye-toe-MYE-sin) belongs to the group of medicines known as antineoplastics. It is used to treat some kinds of cancer. Mitomycin interferes with more...

ofloxacin otic ofloxacin otic
Generic Name: ofloxacin otic (oh FLOCKS a sin OH tic) Brand Names: Floxin Otic What is ofloxacin otic? Ofloxacin is a fluoroquinolone antibiotic. Ofloxacin fights bacteria in the body. Ofloxacin is used to treat ear infections. Ofloxacin otic may also be used for purposes other than thos more...

Parcopa Parcopa
Generic Name: carbidopa and levodopa Dosage Form: Orally disintegrating tablets Description Parcopa™  (carbidopa-levodopa orally disintegrating tablets) is a combination of carbidopa and levodopa for the treatment of Parkinson’s disease and syndrome. Parcopa™  is an or more...