Methazolamide

236.27

236.27

209-066-7

W733B0S9SD|DA43GW06P1

758426

DTXSID1023281

C61318

CRYSTALS FROM WATER

S - Sensory organs

2935009090

139

0.1

white to beige

1.8±0.1 g/cm3

213-214 °C

401.999°C at 760 mmHg

196.9±24.0 °C

1.737

DMSO: soluble 20mg/mL, clear

2-8°C

7.3None

7.30|pKa = 7.30

NONH for all modes of transport

3

20/21/22-40

22-36

AC6350000

Xn

P261-P280-P301 + P312 + P330

H302 + H312 + H332-H351

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

Manufacturers, packers, and distributors of drug and drug products for human use are responsible for complying with the labeling, certification, and usage requirements as prescribed by the Federal Food, Drug, and Cosmetic Act, as amended (secs 201-902, 52 Stat. 1040 et seq., as amended; 21 U.S.C. 321-392).

|Warning|H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]|P201, P202, P261, P264, P270, P271, P280, P281, P301+P312, P302+P352, P304+P312, P304+P340, P308+P313, P312, P322, P330, P363, P405, and P501|Aggregated GHS information provided by 38 companies from 1 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Electrolyte imbalance, development of an acidotic state, and central nervous system effects might be expected to occur in the case of an overdose.

Idiosyncratic, clinically apparent liver injury from acetazolamide and methazolamide is rare, but several instances have been reported as isolated case reports. Acetazolamide is a sulfonamide and cross reactivity to sulfonamide reactions have been reported. The liver injury typically arises after a few days to weeks of therapy and the pattern of serum enzyme elevations is usually hepatocellular or mixed. Immunoallergic features (rash, fever, eosinophilia) are common, but autoantibody formation is not. Both acetazolamide and methazolamide have been linked to Stevens Johnson syndrome and a genetic association has been made with HLA-B*59:01. Hepatic involvement and jaundice can occur in cases of Stevens Johnson syndrome but is generally overshadowed by the severe cutaneous reaction.

DOPAMINE BETA-HYDROXYLASE INHIBITORS, FLA-63 & PICOLINIC ACID, ANTAGONIZED ANTICONVULSANT ACTION OF METHAZOLAMIDE.

55%

For treatment of chronic open-angle glaucoma and acute angle-closure glaucoma

Acetazolamide and methazolamide are carbonic anhydrase inhibitors used as diuretics and in the therapy of glaucoma. Both acetazolamide and methazolamide have been linked to rare cases of clinically apparent drug induced liver disease.

Diuretics

Carbonic Anhydrase Inhibitors; Diuretics|CARBONIC ANHYDRASE INHIBITOR CHEMICALLY RELATED TO ACETAZOLAMIDE & HAVING SAME PROFILE OF CLINICAL INDICATIONS. ... IT IS INDICATED IN PATIENTS WHO DO NOT RESPOND TO ACETAZOLAMIDE OR IN THOSE WHO ARE INTOLERANT TO IT.|ALTHOUGH UNDOUBTEDLY EFFECTIVE IN EVOKING DIURESIS, CARBONIC ANHYDRASE INHIBITORS ARE RELATIVELY INEFFECTIVE COMPARED TO NEWER & MORE EFFICACIOUS AGENTS. /CARBONIC ANHYDRASE INHIBITORS/|ACETAZOLAMIDE HAS BEEN GIVEN TO REDUCE INTRAOCULAR PRESSURE IN MGMNT OF GLAUCOMA. IT MAY...BE EMPLOYED FOR ITS ANTICONVULSANT ACTION FOR BOTH GRAND MAL & PARTICULARLY PETIT MAL EPILEPSY. ...ACETAZOLAMIDE APPEARS TO HAVE BENEFICIAL EFFECT IN MGMNT OF PERIODIC PARALYSIS EVEN WHEN ASSOCIATED WITH HYPOKALEMIA. /ACETAZOLAMIDE/|For more Therapeutic Uses (Complete) data for METHAZOLAMIDE (9 total), please visit the HSDB record page.

CONTRAINDICATIONS, PRECAUTIONS, & ADVERSE REACTIONS ARE SIMILAR TO THOSE OBSERVED WITH ACETAZOLAMIDE & OTHER CARBONIC ANHYDRASE INHIBITORS...|SAFE USE OF THESE AGENTS DURING PREGNANCY HAS NOT BEEN ESTABLISHED. THESE AGENTS ARE CONTRAINDICATED IN PATIENTS WITH IDIOPATHIC RENAL HYPERCHLOREMIC ACIDOSIS, RENAL FAILURE, KNOWN DEPLETION OF SODIUM & OF POTASSIUM, ADDISON'S DISEASE, & PATIENTS KNOWN TO BE SENSITIVE TO THIS CLASS OF DRUGS. /CARBONIC ANHYDRASE INHIBITORS/|IN EDEMATOUS PATIENT, DAILY ADMIN OF ACETAZOLAMIDE LEADS TO METABOLIC TYPE OF ACIDOSIS THAT IS ACCOMPANIED BY LOSS OF DIURETIC RESPONSE TO CONTINUED DRUG THERAPY. /ACETAZOLAMIDE/|CAUTION IS EMPHASIZED IN USE OF CARBONIC ANHYDRASE INHIBITORS IN PATIENTS WITH OBSTRUCTIVE AIRWAY DISEASE.|For more Drug Warnings (Complete) data for METHAZOLAMIDE (9 total), please visit the HSDB record page.

...ITS USEFULNESS IS LIMITED BY RAPID DEVELOPMENT OF TOLERANCE. /ACETAZOLAMIDE/|TOLERANCE MAY DEVELOP IN PATIENTS RECEIVING THERAPY...FOR GLAUCOMA; IN SUCH CASES ONE OF OTHER DRUGS IN THIS GROUP MAY BE EFFECTIVE

Methazolamide is topical carbonic anhydrase inhibitor. Methazolamide is indicated for the reduction of elevated intraocular pressure in patients with open-angle glaucoma or ocular hypertension who are insufficiently responsive to beta-blockers. 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.

Agents that promote the excretion of urine through their effects on kidney function. (See all compounds classified as Diuretics.)|A class of compounds that reduces the secretion of H+ ions by the proximal kidney tubule through inhibition of CARBONIC ANHYDRASES. (See all compounds classified as Carbonic Anhydrase Inhibitors.)

Methazolamide is well absorbed from the gastrointestinal tract.|17 to 23 L|.../CARBONIC ANHYDRASE INHIBITORS/...READILY ABSORBED FROM GI TRACT. PEAK PLASMA CONCN...WITHIN 2 HR. ... EXCRETED BY KIDNEY, BOTH ACTIVE TUBULAR SECRETION & PASSIVE REABSORPTION ARE INVOLVED. /CARBONIC ANHYDRASE INHIBITORS/|.../CARBONIC ANHYDRASE INHIBITORS/ ARE TIGHTLY BOUND TO CARBONIC ANHYDRASE &... PRESENT IN GREATER AMT IN THOSE TISSUES IN WHICH ENZYME IS PRESENT IN HIGH CONCN...ERYTHROCYTES & RENAL CORTEX. /CARBONIC ANHYDRASE INHIBITORS/|SOME CARBONIC ANHYDRASE INHIBITORS DO NOT PENETRATE ERYTHROCYTE. /CARBONIC ANHYDRASE INHIBITORS/|Methazolamide is absorbed more slowly from the GI tract and disappears more slowly from the plasma than does acetazolamide.|For more Absorption, Distribution and Excretion (Complete) data for METHAZOLAMIDE (6 total), please visit the HSDB record page.

AZETAZOLAMIDE DOES NOT UNDERGO METABOLIC ALTERATION. .../SOME CARBONIC ANHYDRASE INHIBITORS/ HAVE BEEN FOUND TO BE INACTIVE IN VITRO BUT ACTIVE IN VIVO, AS RESULT OF N-DEALKYLATION TO FORM AN ACTIVE METABOLITE. /CARBONIC ANHYDRASE INHIBITORS/

14 hours|Half-life is ~14 hours. /From table/

Methazolamide is a potent inhibitor of carbonic anhydrase. Inhibition of carbonic anhydrase in the ciliary processes of the eye decreases aqueous humor secretion, presumably by slowing the formation of bicarbonate ions with subsequent reduction in sodium and fluid transport.|ANTICONVULSANT PROPERTIES...RESEMBLE THOSE OF CARBON DIOXIDE. IN ANIMALS, THEY ABOLISH THE TONIC EXTENSOR COMPONENT OF MAXIMAL ELECTROSHOCK CONVULSIONS, ELEVATE SEIZURE THRESHOLD, & PROTECT AGAINST AUDIOGENIC SEIZURES & THOSE PRODUCED BY WITHDRAWAL FROM HIGH CONCN OF CARBON DIOXIDE. /CARBONIC ANHYDRASE INHIBITORS/|MAJOR PHARMACOLOGICAL ACTION...IS INHIBITION OF ENZYME CARBONIC ANHYDRASE. STUDIES WITH PURIFIED ENZYME HAVE SHOWN THAT INHIBITION IS NONCOMPETITIVE. NONCATALYZED HYDRATION OR DEHYDRATION REACTION CAN TAKE PLACE...IN ABSENCE OF ENZYME. /CARBONIC ANHYDRAS INHIBITORS/|MORE THAN 99% OF ENZYME ACTIVITY IN THE KIDNEY MUST BE INHIBITED BEFORE PHYSIOLOGICAL EFFECTS BECOME APPARENT. THE ENZYME ITSELF IS DOMINANT TISSUE COMPONENT TO WHICH THE INHIBITORS BECOME BOUND. /CARBONIC ANHYDRASE INHIBITORS/|FOLLOWING ADMIN OF ACETAZOLAMIDE, THE URINE VOLUME PROMPTLY INCR. NORMALLY ACIDIC PH BECOMES ALKALINE. URINARY CONCN OF BICARBONATE ANION INCR AND IS MATCHED BY SODIUM AND SUBSTANTIAL AMT OF POTASSIUM. /CARBONIC ANHYDRASE INHIBITORS/|...THE DRUG HAS BEEN FOUND TO INHIBIT EPILEPTIC SEIZURES & TO DECR RATE OF SPINAL FLUID FORMATION. EXACT MECHANISMS BY WHICH CARBONIC ANHYDRASE INHIBITION IS RELATED TO THESE CHANGES IN FUNCTION ARE NOT CLEAR, & MULTIPLE FACTORS MAY BE INVOLVED. /CARBONIC ANHYDRASE INHIBITORS/

SERIOUS TOXIC REACTIONS ARE INFREQUENT. WITH LARGE DOSES, MANY PT EXHIBIT DROWSINESS & PARESTHESIAS. ... HYPERSENSITIVITY REACTIONS ARE RELATIVELY RARE. THEY CONSIST IN FEVER, SKIN REACTIONS, BONE-MARROW DEPRESSION, & SULFONAMIDE-LIKE RENAL LESIONS. /ACETAZOLAMIDE/|METHAZOLAMIDE ADMIN 3 TIMES DAILY TO 68-YR-OLD MAN. A CAUSAL RELATIONSHIP BETWEEN METHAZOLAMIDE & STONE FORMATION WAS SUGGESTED.|4 DAYS AFTER TREATMENT WITH METHAZOLAMIDE FOR OPHTHALMOLOGIC PROBLEM HAD BEGUN, A 60-YR-OLD MALE WITH CHRONIC BRONCHITIS DEVELOPED ACUTE RESP FAILURE & METABOLIC ACIDOSIS.|TWO CASES OF APLASTIC ANEMIA, ONE OF WHICH WAS ALMOST CERTAINLY INDUCED BY METHAZOLAMIDE & ONE CASE OF AGRANULOCYTOSIS RELATED TO USE OF METHAZOLAMIDE ARE DESCRIBED.

Methazolamide

METHAZOLAMIDE, USP (NEPTAZANE), IS AVAILABLE AS OFFICIAL 50-MG TABLETS...

Human Drugs -> FDA Approved Drug Products with Therapeutic Equivalence Evaluations (Orange Book) -> Active Ingredients|Pharmaceuticals