Acetazolamide is a strong carbonic anhydrase inhibitor. It is a prescription medicine used for the following conditions:

• To remove extra fluid from the body (diuresis) in people with heart failure.
• Prevention and treatment of mountain sickness (altitude sickness)
• Seizures
• Glaucoma

Common side effects include:

• Paresthesias (tingling, numbness, burning, prickling)
• Ringing in the ears
• Hearing problems
• Loss of appetite
• Changes in taste
• Nausea
• Vomiting
• Diarrhea
• Frequent urination
• Drowsiness
• Confusion

Other less common side effects include:

• Transient myopia
• Sensitivity to light
• Glucose in the urine
• Blood in urine
• Hives
• Headache
• Fever
• Pain at injection site
• Flushing
• Headache
• Anaphylaxis

Possible serious side effects include:

• Liver problems
• Flaccid paralysis
• Stevens-Johnson syndrome (severe skin rash)
• Toxic epidermal necrolysis (severe skin rash)
• Agranulocytosis (decrease in white blood cells)
• Aplastic anemia and other blood disorders
• Metabolic acidosis
• Electrolyte imbalance
• Growth retardation in children
• Seizures

For the treatment of glaucoma: acetazolamide should be used as an adjunct to the usual therapy.

• The usual recommended dose for the treatment of open-angle glaucoma ranges from 250 mg to 1 gram of acetazolamide per day. Treatment with doses >1gram did not offer any additional benefits.
• The usual recommended dose for the treatment of secondary glaucoma and for the preoperative treatment of some cases of closed-angle glaucoma is 250 mg every 4 hours. In more urgent cases, an initial dose of 500 mg followed by 125 mg or 250 mg every 4 hours as be used.

For the treatment of seizures:

• The manufacturer's suggested total daily dose is 8-30 mg per kg in divided doses.
• The optimum range appears to be from 375 to 1000 mg, however, some patients may respond to lower doses.
• When used with other anti-seizure medication, the starting dose of acetazolamide should be 250 mg, and it should then gradually be increased as necessary.

For congestive heart failure:

• To remove excess fluid in patients (diuresis) with congestive heart failure, the starting dose is usually 250 to 375 mg administered once a day in the morning.
• As tolerance may develop with use, this medication should be skipped for a day to allow the kidneys to recover in patients who stop responding to treatment. For best diuresis, acetazolamide should be given on alternate days, or for two days followed by one day off and then repeat.

For the treatment of excess water retention caused by medication:

• The usual recommended dose is 250 to 375 mg once a day for one or two days, alternating with a day of rest.

For acute mountain sickness:

• The usual recommended dose is 500 mg to 1000 mg per day in divided doses.
• 1000 mg is recommended in cases of rapid ascent.
• Preferably, treatment should be started 24-48 hours before ascent and continued for 48 hours while at high altitude, or longer as necessary to control symptoms.

• Acetazolamide should not be used with other carbonic anhydrase inhibitors such as methazolamide (Neptazane). Use of two carbonic anhydrase inhibitors may cause dangerously low levels of blood potassium (hyponatremia).

• There are no adequate studies evaluating the use of acetazolamide during pregnancy. Evidence of birth defects was observed with administration of oral and injectable acetazolamide in mice, rats, hamsters, and rabbits. Therefore, acetazolamide should only be used during pregnancy if the potential benefit of treatment outweighs the potential risk to the unborn baby. Acetazolamide is classified as FDA pregnancy risk category C.
• It is not known whether acetazolamide is excreted into human milk. Because many drugs are excreted into human milk and can cause side effects in the nursing infant, the manufacturer recommends that patients should discontinue nursing or discontinue acetazolamide, taking into account the importance of treatment to the mother. However, according to the American Academy of Pediatrics, acetazolamide is usually considered to be compatible with breast-feeding.

What preparations of Diamox, Diamox Sequels (acetazolamide) are available?

• Oral tablets: 125 and 250 mg
• Oral capsules extended release (12hr): 500 mg
• Powder for injection: 500 mg

How should I keep Diamox, Diamox Sequels (acetazolamide) stored?

• All oral preparations of acetazolamide should be stored at room temperature.
• Before mixing, injection acetazolamide should be stored at room temperature, between 20 C and 25 C (68 F and 77) F.
• After mixing, acetazolamide injection should be stored in the refrigerator, between 2.2 C and 7.7 C (36 F and 46 F) and used within 12 hours of mixing.

How does Diamox, Diamox Sequels (acetazolamide) work?

• Carbonic anhydrase is an enzyme found within the red blood cells and helps to regulate the acidity and fluid balance in various organs throughout the body. Carbonic anhydrase catalyzes a reversible reaction that converts carbon dioxide and water into carbonic acid, which can then breakdown into protons and bicarbonate ions.
• In the kidneys and the eyes, carbonic anhydrase promotes the reaction that produces bicarbonate ions and acid to regulate the amount of fluid within these organs. When the delicate balance of this reaction is disturbed, medical problems such as glaucoma and excess fluid retention (edema) may occur. Beneficial effects observed in the treatment of glaucoma include decreases in the secretion of aqueous humor in the eye and intraocular pressure.
• When used as a diuretic (water-pill) in patients who have abnormal fluid retention (for example, heart failure), acetazolamide works in the kidney to promote a reversible reaction that results in the loss of bicarbonate, which carries with it sodium, water, and potassium. In-addition to causing diuresis (water loss), the urine becomes more alkaline or basic (pH increases). Alkalization of the urine causes an increase in the reabsorption of ammonia by the renal tubules.
• Acetazolamide is also used to treat and prevent symptoms of acute mountain sickness (AMS) such as headache, nausea, shortness of breath, dizziness, drowsiness, and fatigue. Compared to placebo, 250 mg acetazolamide every 8-12 hours or 500 mg controlled-release capsule once daily was effective in preventing symptoms of acute mountain sickness before and during rapid ascent to altitude. Compared to placebo, acetazolamide treated patients experienced fewer and/or less severe symptoms, had better lung function, and experienced less difficulty in sleeping.
• Acetazolamide is also used with other medications to treat certain forms of seizures.