Acetazolamide (extended-release capsule)

Acetazolamide (extended-release capsule)
	Adult Indications & Dosage
	Pediatric Indications & Dosage
	Contraindications
	Warnings & Precautions
	Adverse Reactions
	Drug Interactions
	Use in Specific Populations
	Administration & Monitoring
	Overdosage
	Pharmacology
	Clinical Studies
	How Supplied
	Images
	Patient Counseling Information
	Precautions with Alcohol
	Brand Names
	Look-Alike Names

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Gerald Chi

Disclaimer

WikiDoc MAKES NO GUARANTEE OF VALIDITY. WikiDoc is not a professional health care provider, nor is it a suitable replacement for a licensed healthcare provider. WikiDoc is intended to be an educational tool, not a tool for any form of healthcare delivery. The educational content on WikiDoc drug pages is based upon the FDA package insert, National Library of Medicine content and practice guidelines / consensus statements. WikiDoc does not promote the administration of any medication or device that is not consistent with its labeling. Please read our full disclaimer here.

Overview

Acetazolamide (extended-release capsule) is a carbonic anhydrase inhibitor that is FDA approved for the {{{indicationType}}} of chronic primary open-angle glaucoma and secondary glaucoma. Acetazolamide is also indicated for the prevention or amelioration of symptoms associated with acute mountain sickness despite gradual ascent. Common adverse reactions include dizziness and lightheadedness.

Adult Indications and Dosage

FDA-Labeled Indications and Dosage (Adult)

Glaucoma

Dosing Information

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.
In those unusual instances where adequate control is not obtained by the twice-a-day administration of Acetazolamide, the desired control may be established by means of Acetazolamide (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

Dosing Information

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.

Off-Label Use and Dosage (Adult)

Guideline-Supported Use

There is limited information regarding Off-Label Guideline-Supported Use of Acetazolamide in adult patients.

Non–Guideline-Supported Use

Glaucoma following surgery; Prophylaxis

Dosing Information

500 mg PO 1 hour postoperatively

Macular retinal edema

Dosing Information

500 mg PO qd for 4 weeks

Periodic ataxia

Dosing Information

Doses of 250 to 1000 mg/day have eliminated or decreased the frequency and severity of symptoms such as nausea and vomiting, diplopia, and nystagmus.

Pediatric Indications and Dosage

FDA-Labeled Indications and Dosage (Pediatric)

The safety and effectiveness of acetazolamide in pediatric patients below the age of 12 years have not been established. Growth retardation has been reported in children receiving long-term therapy, believed secondary to chronic acidosis.

Off-Label Use and Dosage (Pediatric)

Guideline-Supported Use

There is limited information regarding Off-Label Guideline-Supported Use of Acetazolamide in pediatric patients.

Non–Guideline-Supported Use

There is limited information regarding Off-Label Non–Guideline-Supported Use of Acetazolamide in pediatric patients.

Contraindications

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.

Hyponatremia and hypokalemia

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.

Cirrhosis

Acetazolamide is contraindicated in patients with cirrhosis because of the risk of development of hepatic encephalopathy.

Chronic non-congestive angle-closure glaucoma

Long-term administration of Acetazolamide 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.

Warnings

Fatalities have occurred, although rarely, due to severe reactions to sulfonamides including Stevens-Johnson syndrome, toxic epidermal necrolysis, fulminant hepatic necrosis, anaphylaxis, agranulocytosis, aplastic anemia, and other blood dyscrasias. Sensitizations may recur when a sulfonamide is readministered irrespective of the route of administration. If signs of hypersensitivity or other serious reactions occur, discontinue use of this drug. Caution is advised for patients receiving concomitant high-dose aspirin and Acetazolamide, as anorexia, tachypnea, lethargy, metabolic acidosis, coma, and death have been reported.

Increasing the dose does not increase the diuresis and may increase the incidence of drowsiness and/or paresthesia. Increasing the dose often results in a decrease in diuresis. Under certain circumstances, however, very large doses have been given in conjunction with other diuretics in order to secure diuresis in complete refractory failure.

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.

Adverse Reactions

Clinical Trials Experience

There is limited information regarding Clinical Trial Experience of acetazolamide in the drug label.

Postmarketing Experience

Body as a whole

Headache, malaise, fatigue, fever, pain at injection site, flushing, growth retardation in children, flaccid paralysis, anaphylaxis.

Digestive

Gastrointestinal disturbances such as nausea, vomiting, diarrhea.

Hematological/Lymphatic

Blood dyscrasias such as aplastic anemia, agranulocytosis, leukopenia, thrombocytopenic purpura, melena.

Hepato-biliary disorders

Abnormal liver function, cholestatic jaundice, hepatic insufficiency, fulminant hepatic necrosis.

Metabolic/Nutritional

Metabolic acidosis, electrolyte imbalance, including hypokalemia, hyponatremia, osteomalacia with long-term phenytoin therapy, loss of appetite, taste alteration, hyper/hypoglycemia.

Nervous

Drowsiness, paresthesia (including numbness and tingling of extremities and face), depression, excitement, ataxia, confusion, convulsions, dizziness.

Skin

Allergic skin reactions including urticaria, photosensitivity, Stevens- Johnson syndrome, toxic epidermal necrolysis.

Special senses

Hearing disturbances, tinnitus, transient myopia.

Drug Interactions

Aspirin

Caution is advised for patients receiving concomitant high-dose aspirin and Acetazolamide, as anorexia, tachypnea, lethargy, metabolic acidosis, coma, and death have been reported.

Anticonvulsants

Acetazolamide modifies phenytoin metabolism with increased serum levels of phenytoin. This may increase or enhance the occurrence of osteomalacia in some patients receiving chronic phenytoin therapy. Caution is advised in patients receiving chronic concomitant therapy. By decreasing the gastrointestinal absorption of primidone, Acetazolamide may decrease serum concentrations of primidone and its metabolites, with a consequent possible decrease in anticonvulsant effect. Caution is advised when beginning, discontinuing, or changing the dose of Acetazolamide in patients receiving primidone.

Carbonic anhydrase inhibitors

Because of possible additive effects with other carbonic anhydrase inhibitors, concomitant use is not advisable.

Folic acid antagonists

Acetazolamide may increase the effects of other folic acid antagonists. Acetazolamide decreases urinary excretion of amphetamine and may enhance the magnitude and duration of their effect.

Quinidine

Acetazolamide reduces urinary excretion of quinidine and may enhance its effect.

Methenamine

Acetazolamide may prevent the urinary antiseptic effect of methenamine.

Lithium

Acetazolamide increases lithium excretion and the lithium may be decreased.

Sodium bicarbonate

Acetazolamide and sodium bicarbonate used concurrently increase the risk of renal calculus formation. Acetazolamide may elevate cyclosporine levels.

Drug/laboratory test interactions

Sulfonamides may give false negative or decreased values for urinary phenolsulfonphthalein and phenol red elimination values for urinary protein, serum non-protein, and serum uric acid.
Acetazolamide may produce an increased level of crystals in the urine.
Acetazolamide interferes with the HPLC method of assay for theophylline. Interference with the theophylline assay by acetazolamide depends on the solvent used in the extraction; acetazolamide may not interfere with other assay methods for theophylline.

Use in Specific Populations

Pregnancy

Pregnancy Category (FDA): C

Teratogenic effects

Acetazolamide, administered orally or parenterally, has been shown to be teratogenic (defects of the limbs) in mice, rats, hamsters, and rabbits. 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.
Pregnancy Category (AUS): B3 There is no Australian Drug Evaluation Committee (ADEC) guidance on usage of Acetazolamide (extended-release capsule) in women who are pregnant.

Labor and Delivery

There is no FDA guidance on use of Acetazolamide (extended-release capsule) during labor and delivery.

Nursing Mothers

Because of the potential for serious adverse reactions in nursing infants from Acetazolamide, a decision should be made whether to discontinue nursing or to discontinue the drug taking into account the importance of the drug to the mother. Acetazolamide should only be used by nursing women if the potential benefit justifies the potential risk to the child.

Pediatric Use

The safety and effectiveness of Acetazolamide in pediatric patients below the age of 12 years have not been established. Growth retardation has been reported in children receiving long-term therapy, believed secondary to chronic acidosis.

Geriatic Use

Metabolic acidosis, which can be severe, may occur in the elderly with reduced renal function. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and concomitant disease or other drug therapy.

Gender

There is no FDA guidance on the use of Acetazolamide (extended-release capsule) with respect to specific gender populations.

Race

There is no FDA guidance on the use of Acetazolamide (extended-release capsule) with respect to specific racial populations.

Renal Impairment

There is no FDA guidance on the use of Acetazolamide (extended-release capsule) in patients with renal impairment.

Hepatic Impairment

There is no FDA guidance on the use of Acetazolamide (extended-release capsule) in patients with hepatic impairment.

Females of Reproductive Potential and Males

There is no FDA guidance on the use of Acetazolamide (extended-release capsule) in women of reproductive potentials and males.

Immunocompromised Patients

There is no FDA guidance one the use of Acetazolamide (extended-release capsule) in patients who are immunocompromised.

Administration and Monitoring

Administration

Oral

Monitoring

Electrolyte Imbalances

Acetazolamide treatment may cause electrolyte imbalances, including hyponatremia and hypokalemia, as well as metabolic acidosis. Therefore, periodic monitoring of serum electrolytes is recommended.

Hematologic Distrubances

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.

IV Compatibility

Solution

Compatible

Solution 1
Solution 2
Solution 3

Not Tested

Solution 1
Solution 2
Solution 3

Variable

Solution 1
Solution 2
Solution 3

Incompatible

Solution 1
Solution 2
Solution 3

Y-Site

Compatible

Solution 1
Solution 2
Solution 3

Not Tested

Solution 1
Solution 2
Solution 3

Variable

Solution 1
Solution 2
Solution 3

Incompatible

Solution 1
Solution 2
Solution 3

Admixture

Compatible

Solution 1
Solution 2
Solution 3

Not Tested

Solution 1
Solution 2
Solution 3

Variable

Solution 1
Solution 2
Solution 3

Incompatible

Solution 1
Solution 2
Solution 3

Syringe

Compatible

Solution 1
Solution 2
Solution 3

Not Tested

Solution 1
Solution 2
Solution 3

Variable

Solution 1
Solution 2
Solution 3

Incompatible

Solution 1
Solution 2
Solution 3

TPN/TNA

Compatible

Solution 1
Solution 2
Solution 3

Not Tested

Solution 1
Solution 2
Solution 3

Variable

Solution 1
Solution 2
Solution 3

Incompatible

Solution 1
Solution 2
Solution 3

Overdosage

Acute Overdose

Management

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.

Pharmacology

Template:Px

Acetazolamide (extended-release capsule)
Systematic (IUPAC) name
N-(5-sulfamoyl-1,3,4-thiadiazol-2-yl)acetamide
Identifiers
CAS number	59-66-5
ATC code	S01EC01
PubChem	1986
DrugBank	DB00819
Chemical data
Formula	Template:OrganicBox atom Template:OrganicBox atom Template:OrganicBox Template:OrganicBox Template:OrganicBox Template:OrganicBox Template:OrganicBox Template:OrganicBox Template:OrganicBox Template:OrganicBox Template:OrganicBox Template:OrganicBox Template:OrganicBox Template:OrganicBox atom Template:OrganicBox Template:OrganicBox atom Template:OrganicBox Template:OrganicBox Template:OrganicBox atom Template:OrganicBox Template:OrganicBox Template:OrganicBox Template:OrganicBox
Mol. mass	222.245 g/mol
SMILES	eMolecules & PubChem
Pharmacokinetic data
Bioavailability	?
Metabolism	None
Half life	2-4 hours
Excretion	Urine (90%)
Therapeutic considerations
Pregnancy cat.	B3(AU) C(US)
Legal status	Prescription Only (S4)(AU) ?(CA) POM(UK) [[Prescription drug\|Template:Unicode-only]](US)
Routes	oral or intravenous

Mechanism of Action

(Description)

Structure

(Description with picture)

Pharmacodynamics

(Description)

Pharmacokinetics

(Description)

Nonclinical Toxicology

(Description)

Clinical Studies

Condition 1

(Description)

Condition 2

(Description)

Condition 3

(Description)

How Supplied

(Description)

Storage

There is limited information regarding Acetazolamide (extended-release capsule) Storage in the drug label.

Images

Drug Images

{{#ask: Page Name::Acetazolamide (extended-release capsule) |?Pill Name |?Drug Name |?Pill Ingred |?Pill Imprint |?Pill Dosage |?Pill Color |?Pill Shape |?Pill Size (mm) |?Pill Scoring |?NDC |?Drug Author |format=template |template=DrugPageImages |mainlabel=- |sort=Pill Name }}

Package and Label Display Panel

{{#ask: Label Page::Acetazolamide (extended-release capsule) |?Label Name |format=template |template=DrugLabelImages |mainlabel=- |sort=Label Page }}

Patient Counseling Information

Adverse reactions common to all sulfonamide derivatives may occur: anaphylaxis, fever, rash (including erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis), crystalluria, renal calculus, bone marrow depression, thrombocytopenic purpura, hemolytic anemia, leukopenia, pancytopenia, and agranulocytosis. Caution is advised for early detection of such reactions and the drug should be discontinued and appropriate therapy instituted. 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, metabolic acidosis, coma, and death have been reported (see WARNINGS). Both increases and decreases in blood glucose have been described in patients treated with acetazolamide. This should be taken into consideration in patients with impaired glucose tolerance or diabetes mellitus. Acetazolamide treatment may cause electrolyte imbalances, including hyponatremia and hypokalemia, as well as metabolic acidosis. Therefore, periodic monitoring of serum electrolytes is recommended. Particular caution is recommended in patients with conditions that are associated with, or predispose a patient to, electrolyte and acid/base imbalances, such as patients with impaired renal function (including elderly patients; see PRECAUTIONS, Geriatric Use), patients with diabetes mellitus, and patients with impaired alveolar ventilation. Some adverse reactions to acetazolamide, such as drowsiness, fatigue, and myopia, may impair the ability to drive and operate machinery.

Precautions with Alcohol

Alcohol-Acetazolamide interaction has not been established. Talk to your doctor about the effects of taking alcohol with this medication.

Brand Names

Acetazolamide

Look-Alike Drug Names

(Paired Confused Name 1a) — (Paired Confused Name 1b)
(Paired Confused Name 2a) — (Paired Confused Name 2b)
(Paired Confused Name 3a) — (Paired Confused Name 3b)

Drug Shortage Status

Drug Shortage

Price

References

The contents of this FDA label are provided by the National Library of Medicine.

{{#subobject:

 |Page Name=Acetazolamide (extended-release capsule)
 |Pill Name=Acetazolamide (acetazolamide) capsule, extended release 500mg.jpg
 |Drug Name=Acetazolamide
 |Pill Ingred=D&C RED NO. 28, D&C YELLOW NO. 10, FD&C BLUE NO. 1, FD&C BLUE NO. 2, FD&C RED NO. 40, GELATIN, CELLULOSE, MICROCRYSTALLINE, PROPYLENE GLYCOL, SODIUM LAURYL SULFATE, FERROSOFERRIC OXIDE, TALC, TITANIUM DIOXIDE|+sep=;
 |Pill Imprint=Acetazolamide;754
 |Pill Dosage=500 mg
 |Pill Color=Orange|+sep=;
 |Pill Shape=Capsule
 |Pill Size (mm)=23mm
 |Pill Scoring=
 |Pill Image=
 |Drug Author=Duramed Pharmaceuticals, Inc.
 |NDC=51285-754

}}

{{#subobject:

 |Label Page=Acetazolamide (extended-release capsule)
 |Label Name=Acetazolamide (acetazolamide) capsule, extended release label display.jpeg

}}