Diamox

Common Side Effects of Acetazolamide

Tell your doctor if any of the following side effects become severe or don't go away:

• Changes in taste or loss of appetite
• Nausea
• Vomiting

Serious Side Effects of Acetazolamide

Tell your doctor right away if you experience any of the following serious side effects:

• Yellowing of the skin or eyes (jaundice)
• Numbness or tingling in your arms or legs
• Drowsiness or tiredness
• Headache
• Fever
• Rash
• Confusion
• Seizures
• Sore throat
• Blood in urine
• Pelvic pain or painful urination
• Unusual bleeding or bruising
• Severe allergic reaction (indicated by hives, rash, itching, chest tightness, or swelling of the face, lips, tongue, or throat)

Diamox is part of the drug class:

• Carbonic anhydrase inhibitors

Serious side effects have been reported with Diamox including:

• paresthesias, particularly a “tingling” feeling in the extremities. Occurs most often early in therapy.
• tinnitus (noise or ringing in the ears)
• hypersensitivity (severe allergic reaction). Signs of a hypersensitivity reaction, which include the following:
  • chest pain
  • swelling of the face, eyes, lips, tongue, arms, or legs
  • difficulty breathing or swallowing
  • fainting
  • rash
• loss of blood sugar control. Caution is advised in those with impaired glucose (blood sugar) tolerance or in those with diabetes.
• electrolyte imbalances. Electrolytes are minerals in your body that help your body function normally. An imbalance could lead to abnormalities such as arrhythmias (with low or high levels of potassium), a change in body fluid (due to low or high levels of sodium), and altered acidity levels of your blood.
• anaphylaxis, fever, rash (including erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis)
• decrease in blood counts

Diamox may cause dizziness, drowsiness, or blurred vision. Do not drive or operate heavy machinery until you know how Diamox affect you.

Do not take Diamox if you:

• have an allergic reaction to Diamox or any of its ingredients
• have a history of an allergic reaction to sulfonamides
• have lowered levels of sodium and/or potassium blood levels in cases of kidney and liver disease or dysfunction, in suprarenal gland failure, and in hyperchloremic acidosis
• have a history of cirrhosis because of the risk of development of hepatic encephalopathy
• are using Diamox for a prolonged duration and also have chronic non-congestive angle-closure glaucoma

Tell your doctor if you are breastfeeding or plan to breastfeed.

Because of the possibility for serious negative reactions in nursing infants from Diamox, a decision should be made whether to stop nursing or to stop the drug. Diamox should only be used by nursing women if the benefit outweighs the risk to the child.

Take Diamox exactly as prescribed.

This medication comes in a tablet form and can be given up to four times a day.

This medication comes in an extended release capsule form and is taken up to two times a day, with or without food.

• Do not chew, divide, or break Diamox capsules. Swallow capsules whole.

Diamox is also available in an injectable form to be given directly into a vein (IV) by a healthcare professional.

If you miss a dose, take the missed dose as soon as you remember. If it is almost time for the next dose, skip the missed dose and take your next dose at the regular time. Do not take two doses of Diamox at the same time.

• Store Diamox capsules and tablets at room temperature between 20° to 25°C (68° to 77°F).
• Keep this and all medicines out of the reach of children.

Administration

Administer orally or by direct IV injection.c d e

Do not administer IM; injection is painful.b e

Oral Administration

When an oral liquid preparation is needed, crush the appropriate number of tablets and suspend in a highly flavored carbohydrate syrup.a Can suspend up to 500 mg of acetazolamide in 5 mL of syrup; suspensions containing 250 mg per 5 mL are more palatable.a Alternatively, soften a tablet in 2 teaspoonsful of hot water and add 2 teaspoonsful of honey or syrup; swallow immediately.a

When the extended-release capsules are used for glaucoma, if adequate response is not achieved with twice-daily administration of this preparation, consider using other acetazolamide preparations that are administered more frequently (i.e., tablet, parenteral preparation) to achieve IOP control.d

IV Administration

For solution and drug compatibility information, see Compatibility under Stability.

Administer IV when rapid lowering of IOP is necessary or if patient is unable to take oral medication.a e

Reconstitute vial containing 500 mg of acetazolamide with 5 mL of sterile water for injection to provide a solution containing 100 mg/mL.a e

Dosage

Available as acetazolamide (oral preparations) and acetazolamide sodium; dosage expressed in terms of acetazolamide.c d e

Adjust dosage based on patient response and requirements.a

Pediatric Patients

8–30 mg/kg or 300–900 mg/m2 daily in 3 divided doses has been used.a

Children ≥12 years of age: 500 mg twice daily as extended-release capsules.d

Children ≥12 years of age: 500 mg twice daily as extended-release capsules.d

5–10 mg/kg every 6 hours has been used.a

Children ≥12 years of age: 500 mg once or twice daily as extended-release capsules.d Initiate 24–48 hours before ascent; continue for 48 hours while at high altitude or longer if needed to control symptoms.d

8–30 mg/kg daily in divided doses has been used.a c

5 mg/kg or 150 mg/m2 once daily in the morning has been used.a

Adults

Conventional tablets: 250 mg to 1 g daily.c For daily dosages >250 mg, administer in divided doses.c

Extended-release capsules: 500 mg twice daily.d

250 mg to 1 g daily.e For daily dosages >250 mg, administer in divided doses.e

Conventional tablets: 250 mg every 4 hours.c Some patients respond to short-term therapy with 250 mg twice daily.c

Extended-release capsules: 500 mg twice daily.d

250 mg every 4 hours.e Some patients respond to short-term therapy with 250 mg twice daily.e

Conventional tablets: 250 mg every 4 hours. a c Alternatively, 250 mg twice daily or an initial dose of 500 mg followed by 125–250 mg every 4 hours.a c

Extended-release capsules: 500 mg twice daily.d

250 mg every 4 hours.e Alternatively, 250 mg twice daily or an initial dose of 500 mg followed by 125–250 mg every 4 hours.e

Conventional tablets and extended-release capsules: 500 mg to 1 g daily in divided doses.c d Initiate 24–48 hours before ascent; continue for 48 hours while at high altitude or longer if needed to control symptoms.c d

125–250 mg twice daily starting 24 hours before ascent has been effective for prevention of acute mountain sickness; 500 mg (as extended-release capsules) every 24 hours also has been effective.f 750 mg daily may be more effective than 500 mg daily.f

125 mg at bedtime has been used for the management of high-altitude sleep disorders.f

For treatment of acute mountain sickness, some experts recommend 250 mg given within 24 hours of onset of symptoms and a second 250-mg dose 8 hours later.f

Conventional tablets: 8–30 mg/kg daily in divided doses.c

Usual dosage range: 375 mg to 1 g daily.c

When used in conjunction with other anticonvulsants, initiate at 250 mg once daily and increase dosage as needed.c

8–30 mg/kg daily in divided doses; usual dosage range is 375 mg to 1 g daily.e

When given in conjunction with other anticonvulsants, initiate at 250 mg once daily and increase dosage as needed.e

Conventional tablets: Initially, 250–375 mg (5 mg/kg) once daily in the morning.c

If patient fails to lose edema fluid after initial response, hold drug for 1 day. c To avoid loss of diuretic effect, administer intermittently (on alternate days or for 2 days followed by a drug-free day).c

Initially, 250–375 mg (5 mg/kg) once daily in the morning.e

If patient fails to lose edema fluid after initial response, hold drug for 1 day.e To avoid loss of diuretic effect, administer intermittently (on alternate days or for 2 days followed by a drug-free day).e

Conventional tablets: 250–375 mg once daily for 1 or 2 days, alternating with a drug-free day.c

250–375 mg once daily for 1 or 2 days, alternating with a drug-free day.e

250 mg 2 to 3 times daily has been used.a

Prescribing Limits

When used in glaucoma or seizure disorders, dosage >1 g daily is not associated with additional clinical benefit.c d e

When used for diuresis, increasing dosage does not produce greater response and may result in decreased response.c d e

Special Populations

Geriatric Patients

Select dosage with caution because of age-related decreases in hepatic, renal, and/or cardiac function and concomitant disease and drug therapy.d

• Risk of adverse effects, including sensitivity reactions; discontinue therapy and consult clinician if signs of sensitivity occur.c d e

• When used to prevent acute mountain sickness, importance of gradual ascent.c f Use of acetazolamide does notobviate need to stop ascent if acute mountain sickness develops or descend if severe forms of altitude sickness (e.g., high attitude pulmonary or cerebral edema) occur.c f

• Potential for the drug to impair mental alertness or impair vision (myopia); use caution when driving a vehicle or operating machinery until effects on individual are known.d

• Advise patients with pulmonary obstruction or emphysema that the drug may precipitate or aggravate acidosis.c d

• Advise patients with diabetes or impaired glucose tolerance that increases and decreases in blood glucose have occurred in acetazolamide-treated patients.d

• Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs (e.g., high-dose aspirin), as well as concomitant diseases.c d e

• Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed.c d e

• Importance of informing patients of other precautionary information.c d e (See Cautions.)

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name

Hypersensitivity to acetazolamide or any excipients in the formulation. Since acetazolamide is a sulfonamide derivative, cross sensitivity between acetazolamide, sulfonamides and other sulfonamide derivatives is possible.

Acetazolamide therapy is contraindicated in situations in which sodium and/or potassium blood serum levels are depressed, in cases of marked kidney and liver disease or dysfunction, in suprarenal gland failure, and in hyperchloremic acidosis. It is contraindicated in patients with cirrhosis because of the risk of development of hepatic encephalopathy.

Long-term administration of Diamox is contraindicated in patients with chronic non-congestive angle-closure glaucoma since it may permit organic closure of the angle to occur while the worsening glaucoma is masked by lowered intraocular pressure.

Glaucoma

The recommended dosage is 1 capsule (500 mg) two times a day. Usually 1 capsule is administered in the morning and 1 capsule in the evening. It may be necessary to adjust the dose, but it has usually been found that dosage in excess of 2 capsules (1 g) does not produce an increased effect. The dosage should be adjusted with careful individual attention both to symptomatology and intraocular tension. In all cases, continuous supervision by a physician is advisable.

In those unusual instances where adequate control is not obtained by the twice-a-day administration of Diamox SEQUELS, the desired control may be established by means of Diamox (tablets or parenteral). Use tablets or parenteral in accordance with the more frequent dosage schedules recommended for these dosage forms, such as 250 mg every four hours, or an initial dose of 500 mg followed by 250 mg or 125 mg every four hours, depending on the case in question.

Acute Mountain Sickness

Dosage is 500 mg to 1000 mg daily, in divided doses using tablets or extended-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 48 hours before ascent and to continue for 48 hours while at high altitude, or longer as necessary to control symptoms.