METHAZOLAMIDE tablet

Country: United States

Language: English

Source: NLM (National Library of Medicine)

Active ingredient:

METHAZOLAMIDE (UNII: W733B0S9SD) (METHAZOLAMIDE - UNII:W733B0S9SD)

Available from:

Physicians Total Care, Inc.

INN (International Name):

METHAZOLAMIDE

Composition:

METHAZOLAMIDE 50 mg

Administration route:

ORAL

Prescription type:

PRESCRIPTION DRUG

Therapeutic indications:

Methazolamide is 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. 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.

Product summary:

Methazolamide tablets, USP for oral administration are available as: Store at 20°-25°C (68°-77°F) (see USP Controlled Room Temperature). Dispense in a tight, light-resistant container.

Authorization status:

Abbreviated New Drug Application

Summary of Product characteristics

METHAZOLAMIDE - METHAZOLAMIDE TABLET
PHYSICIANS TOTAL CARE, INC.
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METHAZOLAMIDE TABLETS, USP
DESCRIPTION
Methazolamide, a sulfonamide derivative, is a white crystalline
powder, weakly acidic, and slightly
soluble in water, alcohol and acetone. It is available as 25 mg and 50
mg tablets. The chemical name for
methazolamide is _N_
-[5-(aminosulfonyl)-3-methyl-1,3,4-thiadiazol-2(3_H_)-ylidene]-acetamide
and it has
the following structural formula:
Methazolamide tablets, USP contain 25 mg or 50 mg of methazolamide.
Inactive ingredients:
croscarmellose sodium, hydroxypropyl methylcellulose, lactose
(monohydrate), magnesium stearate,
microcrystalline cellulose, and sodium lauryl sulfate.
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 b.i.d., 50 mg b.i.d. and 100 mg b.i.d.
demonstrated a linear relationship between
plasma methazolamide levels and methazolamide dose. Peak plasma
concentrations (C
) for the 25 mg,
50 mg and 100 mg b.i.d. 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) were 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 extracellular fluid. The
mean apparent volume of distribution
(V
/F) ranges from 17 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 b.i.d., 50 mg
b.i.d. and 100 mg b.i.d., respectively.
The mean steady-state plasma elimination half-life for methazolamide
is approximately 14 hou