Acetazolamide Capsules

Name: Acetazolamide Capsules

Spl unclassified

Acetazolamide Extended-Release Capsules

Rx only

Acetazolamide Capsules Description

Acetazolamide Extended-Release Capsules are an inhibitor of the enzyme carbonic anhydrase. Acetazolamide is a white to faintly yellowish white crystalline, odorless powder, weakly acidic, very slightly soluble in water and slightly soluble in alcohol. The chemical name for Acetazolamide is N-(5-Sulfamoyl-1,3,4-thiadiazol-2-yl) acetamide and has the following chemical structure:

Each acetazolamide extended-release capsule, for oral administration, contains 500 mg of acetazolamide and the following inactive ingredients:

Microcrystalline cellulose, hydroxypropyl cellulose, pregelatinized starch, talc.

The capsule shell contains gelatin, sodium lauryl sulphate and titanium dioxide. The imprinting ink contains shellac, potassium hydroxide and black iron oxide.

Acetazolamide Capsules - Clinical Pharmacology

Acetazolamide is a potent carbonic anhydrase inhibitor, effective in the control of fluid secretion (e.g., some types of glaucoma), in the treatment of certain convulsive disorders (e.g., epilepsy) and in the promotion of diuresis in instances of abnormal fluid retention (e.g., cardiac edema).

Acetazolamide is not a mercurial diuretic. Rather, it is a non-bacteriostatic sulfonamide possessing a chemical structure and pharmacological activity distinctly different from the bacteriostatic sulfonamides.

Acetazolamide is an enzyme inhibitor that acts specifically on carbonic anhydrase, the enzyme that catalyzes the reversible reaction involving the hydration of carbon dioxide and the dehydration of carbonic acid. In the eye, this inhibitory action of acetazolamide decreases the secretion of aqueous humor and results in a drop in intraocular pressure, a reaction considered desirable in cases of glaucoma and even in certain non-glaucomatous conditions. Evidence seems to indicate that acetazolamide has utility as an adjuvant in treatment of certain dysfunctions of the central nervous system (e.g., epilepsy). Inhibition of carbonic anhydrase in this area appears to retard abnormal, paroxysmal, excessive discharge from central nervous system neurons. The diuretic effect of Acetazolamide is due to its action in the kidney on the reversible reaction involving hydration of carbon dioxide and dehydration of carbonic acid. The result is renal loss of HCO3 ion, which carries out sodium, water, and potassium. Alkalinization of the urine and promotion of diuresis are thus affected. Alteration in ammonia metabolism occurs due to increased reabsorption of ammonia by the renal tubules as a result of urinary alkalinization.

Acetazolamide extended-release capsules provide prolonged action to inhibit aqueous humor secretion for 18 to 24 hours after each dose, whereas tablets act for only 8 to 12 hours. The prolonged continuous effect of acetazolamide extended-release capsule permits a reduction in dosage frequency.

Plasma concentrations of acetazolamide peak from three to six hours after administration of acetazolamide extended-release capsule, compared to one to four hours with tablets. Food does not affect bioavailability of acetazolamide extended-release capsules.

Placebo-controlled clinical trials have shown that prophylactic administration of acetazolamide at a dose of 250 mg every eight to 12 hours (or a 500 mg controlled-release capsule once daily) before and during rapid ascent to altitude results in fewer and/or less severe symptoms of acute mountain sickness (AMS) such as headache, nausea, shortness of breath, dizziness, drowsiness, and fatigue. Pulmonary function (e.g., minute ventilation, expired vital capacity, and peak flow) is greater in the acetazolamide treated group, both in subjects with AMS and asymptomatic subjects. The acetazolamide treated climbers also had less difficulty in sleeping.

Overdosage

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 are required to restore electrolyte and pH balance. The acidotic state can usually be corrected by the administration of bicarbonate.

Despite its high intraerythrocytic distribution and plasma protein binding properties, acetazolamide may be dialyzable. This may be particularly important in the management of acetazolamide overdosage when complicated by the presence of renal failure.

How is Acetazolamide Capsules Supplied

Acetazolamide Extended-Release Capsules are available as 500 mg:

White capsules containing white to off-white pellets, imprinted in black ink (Body:N16; Cap: 548)

Available in bottles of 100 Capsules.

NDC 50742-233-01.

Store at 20° to 25°C [68° to 77°F][See USP controlled room temperature].

To report SUSPECTED ADVERSE REACTIONS, contact Ingenus Pharmaceuticals LLC, toll-free at 1-877-748-1970 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Manufactured for:  Ingenus Pharmaceuticals LLC

                               Orlando, FL 32839-6408

                               Customer toll-free number: 1-877-748-1970

Manufactured by:  Novast Laboratories Ltd.

                               Nantong, China 226009

Iss. 07/2017

Rev. A

I0078

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