What are the indications for acetazolamide (Carbonic Anhydrase Inhibitor)?

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From the Guidelines

Acetazolamide is indicated for the treatment of various conditions, including glaucoma, epilepsy, edema, and altitude sickness. Specifically, it is used to reduce intraocular pressure in glaucoma, as an adjunct in the treatment of certain types of seizures, to reduce edema associated with congestive heart failure, and to prevent and treat acute mountain sickness 1.

Indications

  • Glaucoma: to reduce intraocular pressure
  • Epilepsy: as an adjunct in the treatment of certain types of seizures
  • Edema: to reduce edema associated with congestive heart failure
  • Altitude sickness: to prevent and treat acute mountain sickness
  • Idiopathic intracranial hypertension: to reduce intracranial pressure
  • Obstructive sleep apnea: to reduce sleep apnea intensity

Dosage

The typical dose ranges from 250 mg to 1000 mg per day, depending on the condition being treated. For glaucoma, the usual dose is 250-500 mg orally 1-4 times a day. For epilepsy, the dose is typically 250-1000 mg per day, and for altitude sickness, 250-500 mg orally 2-3 times a day. Treatment duration varies depending on the condition, but generally, it is continued until the underlying condition is resolved or improved 1.

Side effects

Patients should be warned of the adverse side effects of acetazolamide, which include increased risk of diarrhoea, dysgeusia, fatigue, nausea, paraesthesia, tinnitus, vomiting, depression, and rarely renal stones 1.

Special considerations

In patients with obstructive sleep apnea, acetazolamide may reduce sleep apnea intensity by up to 45% 1. In patients with altitude sickness, acetazolamide may reduce the risk of subendocardial ischemia and improve nocturnal oxygen saturation 1. In patients with idiopathic intracranial hypertension, acetazolamide may be used to reduce intracranial pressure 1. In patients with acute promyelocytic leukemia, acetazolamide may be used to treat pseudotumor cerebri 1.

From the FDA Drug Label

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). 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). The indications for acetazolamide are:

  • Glaucoma: to decrease intraocular pressure
  • Epilepsy: as an adjuvant in treatment of certain convulsive disorders
  • Abnormal fluid retention: to promote diuresis in instances of cardiac edema 2

From the Research

Indications for Acetazolamide

The indications for acetazolamide, a carbonic anhydrase inhibitor, include:

  • Epilepsy 3
  • Glaucoma 3, 4
  • Edema 3
  • Altitude sickness 3, 5, 6
  • Idiopathic intracranial hypertension 3, 4
  • Elevated intracranial pressure (ICP) due to cerebrospinal fluid (CSF) leaks 3
  • Acute mountain sickness (AMS) 5, 6
  • Acute angle-closure glaucoma 4
  • Acute heart failure 4
  • Post hypercapnic metabolic alkalosis 4

Off-Label Uses

Off-label uses of acetazolamide may include:

  • Ventilator weaning for chronic obstructive pulmonary disease patients 3
  • Prevention of high-dose methotrexate toxicity 3
  • Prevention of contrast-induced nephropathy 3
  • Treatment of sleep apnea 7

Dosage and Administration

The dosage of acetazolamide ranges from 250 to 4,000 mg daily, divided every 6-12 hours 3. The plasma half-life is 4-8 hours, though the pharmacologic effects of acetazolamide last longer 3. Administration should not be more frequent than every 12 hours if creatinine clearance is less than 50 mL/min 3.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Evaluating off-label uses of acetazolamide.

American journal of health-system pharmacy : AJHP : official journal of the American Society of Health-System Pharmacists, 2018

Research

The role of acetazolamide in critical care and emergency medicine.

Journal of geriatric cardiology : JGC, 2024

Research

Mechanisms of action of acetazolamide in the prophylaxis and treatment of acute mountain sickness.

Journal of applied physiology (Bethesda, Md. : 1985), 2007

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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