Acetazolamide

What is Acetazolamide?

• Acetazolamide (Diamox) is a carbonic anhydrase inhibitor used to treat glaucoma, epilepsy, altitude sickness, periodic paralysis, idiopathic intracranial hypertension (raised brain pressure of unclear cause), urine alkalinization, and heart failure.
• It may be used long term for the treatment of open angle glaucoma and short term for acute angle closure glaucoma until surgery can be carried out.

Acetazolamide Structural Formulae V.1

Acetazolamide 3D ball

Acetazolamide2DACS

What are the uses of this medicine?

Acetazolamide (Diamox) used for the treatment of:

• edema due to congestive heart failure
• drug-induced edema
• centrencephalic epilepsies (petit mal, unlocalized seizures)
• chronic simple (open-angle) glaucoma
• secondary glaucoma
• preoperatively in acute angle-closure glaucoma where delay of surgery is desired in order to lower intraocular pressure
• acute mountain sickness in climbers attempting rapid ascent

How does this medicine work?

• Acetazolamide (a seet" a zol' a mide) and methazolamide (meth" a zol' a mide) are inhibitors of carbonic anhydrase, an enzyme that converts carbon dioxide and water to carbonic acid.
• Inhibition of this enzyme in the kidney causes an alkalization of the urine and diuresis.
• In the eye, inhibition of carbonic anhydrase causes a decrease in intraocular pressure making these agents valuable in the treatment of glaucoma.
• The effects of acetazolamide on acid-base status (causing a mild metabolic acidosis) are also of potential value in managing other conditions including epilepsy, sleep apnea, and acute mountain sickness.

Who Should Not Use this medicine ?

This medicine cannot be used in patients with:

• cirrhosis because of the risk of development of hepatic encephalopathy.
• situations in which sodium and/or potassium blood serum levels are depressed, in cases of marked kidney and liver disease or dysfunction
• with chronic non-congestive angle-closure glaucoma

What drug interactions can this medicine cause?

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Be sure to mention if you are taking any of the following:

• especially amphetamines, aspirin, cyclosporine (Neoral, Sandimmune), medications for depression or irregular heartbeat, diflunisal (Dolobid), digoxin (Lanoxin), diuretics ('water pills'), lithium (Eskalith, Lithobid), phenobarbital, primidone (Mysoline), and vitamins.

Is this medicine FDA approved?

• Acetazolamide came into medical use in 1952.

How should this medicine be used?

Recommended dosage: Glaucoma: chronic simple (open-angle) glaucoma:

• 250 mg to 1 g of acetaZOLAMIDE per 24 hours, usually in divided doses for amounts over 250 mg.

Acute congestive (closed-angle) glaucoma:

• The preferred dosage is 250 mg every four hours, although some cases have responded to 250 mg twice daily on short-term therapy.
• In some acute cases, it may be more satisfactory to administer an initial dose of 500 mg followed by 125 mg or 250 mg every four hours depending on the individual case.

Epilepsy:

• The suggested total daily dose is 8 to 30 mg per kg in divided doses.
• Although some patients respond to a low dose, the optimum range appears to be from 375 to 1000 mg daily.

Congestive Heart Failure:

• For diuresis in congestive heart failure, the starting dose is usually 250 to 375 mg once daily in the morning (5 mg/kg).

Drug-Induced Edema:

• Recommended dosage is 250 to 375 mg of acetaZOLAMIDE once a day for one or two days, alternating with a day of rest.

Acute Mountain Sickness:

• Dosage is 500 mg to 1000 mg daily, in divided doses using tablets or sustained-release capsules as appropriate.
• In circumstances of rapid ascent, such as in rescue or military operations, the higher dose level of 1000 mg is recommended.
• It is preferable to initiate dosing 24 to 28 hours before ascent and to continue for 48 hours while at high altitude, or longer as necessary to control symptoms.

Administration:

• Acetazolamide comes as a tablet and capsule to take by mouth.
• If you are taking the extended-release (long-acting) form of acetazolamide (Diamox Sequels), do not crush or chew the capsules.

What are the dosage forms and brand names of this medicine?

This medicine is available in fallowing doasage form:

• As Acetazolamide comes as a tablet and capsule.
• Acetazolamide is also available in extended release forms (capsules of 500 mg) and as powder for injection.

This medicine is available in fallowing brand namesː

• Diamox

What side effects can this medication cause?

The most common side effects of this medicine include:

• paresthesias
• hearing dysfunction or tinnitus
• loss of appetite
• taste alteration and gastrointestinal disturbances such as nausea, vomiting and diarrhea
• polyuria
• occasional instances of drowsiness and confusion
• Metabolic acidosis
• electrolyte imbalance
• myopia
• urticaria
• melena
• hematuria
• glycosuria
• hepatic insufficiency
• flaccid paralysis
• photosensitivity
• convulsions

• Methazolamide and acetazolamide have similar chemical structures and are related to the sulfonamides and can cause allergic reactions including anaphylaxis, rash, erythema multiforme, Stevens Johnson Syndrome, toxic epidermal necrolysis, fulminant hepatic necrosis, agranulocytosis, aplastic anemia and other blood dyscrasias.

What special precautions should I follow?

• 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. If signs of hypersensitivity or other serious reactions occur, discontinue use of this drug.
• In patients with pulmonary obstruction or emphysema where alveolar ventilation may be impaired, acetaZOLAMIDE, which may precipitate or aggravate acidosis should be used with caution.
• Gradual ascent is desirable to try to avoid acute mountain sickness. If rapid ascent is undertaken and acetaZOLAMIDE is used, it should be noted that such use does not obviate the need for prompt descent if severe forms of high altitude sickness occur. i.e., high altitude pulmonary edema (HAPE) or high-altitude cerebral edema.
• Caution is advised for patients receiving concomitant high-dose aspirin and acetaZOLAMIDE, as anorexia, tachypnea, lethargy, coma and death have been reported
• To monitor for hematologic reactions common to all sulfonamides, it is recommended that a baseline CBC and platelet count be obtained on patients prior to initiating acetaZOLAMIDE therapy and at regular intervals during therapy. If significant changes occur, early discontinuance and institution of appropriate therapy are important. Periodic monitoring of serum electrolytes is recommended.
• This drug may make you drowsy. Do not drive a car or operate machinery until you know how this drug affects you. Remember that alcohol can add to the drowsiness caused by this drug.
• Plan to avoid unnecessary or prolonged exposure to sunlight and to wear protective clothing, sunglasses, and sunscreen. Acetazolamide may make your skin sensitive to sunlight.

What to do in case of emergency/overdose?

Symptoms of overdose may include:

• Electrolyte imbalance, development of an acidotic state, and central nervous effects might be expected to occur.

Management of overdosage:

• No specific antidote is known.
• Treatment should be symptomatic and supportive.
• Serum electrolyte levels (particularly potassium) and blood pH levels should be monitored.

Can this medicine be used in pregnancy?

• Pregnancy Category C.
• There are no adequate and well-controlled studies in pregnant women.
• AcetaZOLAMIDE should be used in pregnancy only if the potential benefit justifies the potential risk to the fetus.

Can this medicine be used in children?

• The safety and effectiveness of acetaZOLAMIDE in children have not been established.

What are the active and inactive ingredients in this medicine?

Active ingredients:

• ACETAZOLAMIDE

Inactive ingredient:

• LACTOSE MONOHYDRATE
• SODIUM STARCH GLYCOLATE TYPE A POTATO
• STARCH, CORN
• CALCIUM STEARATE

Who manufactures and distributes this medicine?

Distributed by:

• Lannett Company, Inc.
• Philadelphia, PA

What should I know about storage and disposal of this medication?

• Store at controlled room temperature 15°-30° C (59°-86° F).
• Dispense in a well-closed container, as defined in the USP.

• Dailymed label info on Acetazolamide
• FDA Acetazolamide

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