Diamox, known generically as acetazolamide, is a carbonic anhydrase inhibitor prescription medication primarily indicated for the management of glaucoma, certain types of seizures, edema due to congestive heart failure, and the prevention or amelioration of symptoms related to acute mountain sickness. It functions by reducing the production of aqueous humor in the eye, thereby lowering intraocular pressure, and by inducing a mild metabolic acidosis, which can stimulate ventilation and facilitate acclimatization to high altitude. Its therapeutic utility is well-established in clinical practice, offering a targeted mechanism of action for specific physiological disturbances.

Features

• Active Ingredient: Acetazolamide
• Drug Class: Carbonic anhydrase inhibitor
• Available Forms: Oral tablets (125 mg, 250 mg), extended-release capsules (500 mg), and injectable solution
• Mechanism of Action: Reversible inhibition of the enzyme carbonic anhydrase
• Onset of Action: Diuretic effect begins within 60-90 minutes; intraocular pressure reduction occurs within 1-2 hours
• Duration: Varies by formulation; standard tablets require BID or TID dosing, while extended-release capsules allow for once-daily administration

Benefits

• Effectively lowers elevated intraocular pressure, helping to preserve optic nerve function in glaucoma patients
• Reduces fluid retention associated with heart failure, mitigating symptoms of edema
• Assists in the prevention and treatment of acute mountain sickness by accelerating acclimatization
• Provides adjunctive therapy for certain seizure disorders, particularly absence seizures
• Offers a non-invasive pharmacological option before surgical interventions for glaucoma
• Can be used pre-operatively to reduce cerebrospinal fluid production

Common use

Diamox is most commonly prescribed for the management of open-angle glaucoma, secondary glaucoma, and pre-operatively in acute angle-closure glaucoma to lower intraocular pressure before iridectomy. It is also frequently utilized for the prophylaxis and treatment of symptoms of acute mountain sickness (AMS) in individuals ascending to altitudes above 3,000 meters. Additionally, it serves as an adjunctive therapy for various forms of epilepsy, particularly absence seizures, and is used to treat edema due to congestive heart failure when other diuretics are insufficient or contraindicated.

Dosage and direction

Dosage must be individualized based on indication, patient response, and formulation. For glaucoma: Adults—250 mg to 1 g per day in divided doses (1-4 times daily). For altitude sickness prophylaxis: 125 mg twice daily, starting 24-48 hours before ascent and continuing for 48 hours after reaching the target altitude. For edema in congestive heart failure: 250-375 mg once daily in the morning. Extended-release capsules should be swallowed whole and not crushed or chewed. Administration with food may minimize gastrointestinal upset. Dosage adjustments are necessary in renal impairment.

Precautions

Patients should maintain adequate hydration to prevent kidney stone formation but avoid excessive fluid intake. Regular monitoring of electrolytes (particularly potassium and bicarbonate), blood counts, and renal function is advised during prolonged therapy. Use with caution in patients with respiratory acidosis or significant pulmonary obstruction. May cause drowsiness or blurred vision; patients should exercise caution when operating machinery or driving until they know how the medication affects them. Photosensitivity reactions have been reported; appropriate sun protection is recommended.

Contraindications

Diamox is contraindicated in patients with known hypersensitivity to acetazolamide or sulfonamides. It should not be used in those with significant hepatic disease or dysfunction, severe renal impairment (CrCl <10 mL/min) or hyperchloremic acidosis. It is contraindicated in adrenocortical insufficiency, hypokalemia, hyponatremia, and in patients with chronic non-congestive angle-closure glaucoma. Concomitant use with high-dose aspirin is contraindicated due to the risk of metabolic acidosis.

Possible side effect

Common adverse reactions include paresthesia (tingling in extremities), loss of appetite, taste alteration (particularly a metallic taste), polyuria, and drowsiness. Gastrointestinal effects such as nausea, vomiting, and diarrhea may occur. Metabolic side effects can include hypokalemia, metabolic acidosis, and hyperglycemia. Less frequently, it may cause transient myopia, sulfonamide-like reactions (rash, urticaria), crystalluria, or kidney stones. Rare but serious side effects include bone marrow suppression, Stevens-Johnson syndrome, and toxic epidermal necrolysis.

Drug interaction

Acetazolamide may potentiate the effects of other diuretics and antihypertensive agents. It can increase the concentration and toxicity of phenytoin, primidone, and salicylates. Concurrent use with other carbonic anhydrase inhibitors should be avoided. It may decrease the excretion of quinidine, amphetamines, and procainamide. The hypokalemic effect can be enhanced by corticosteroids, amphotericin B, and stimulant laxatives. It may antagonize the effects of methenamine compounds.

Missed dose

If a dose is missed, it should be taken as soon as remembered unless it is nearly time for the next scheduled dose. In that case, the missed dose should be skipped, and the regular dosing schedule resumed. Doubling the dose to make up for a missed one is not recommended. For extended-release formulations, which are typically taken once daily, the same principle applies. Consistency in dosing is important for maintaining therapeutic effect, particularly for glaucoma management.

Overdose

Symptoms of overdose may include electrolyte imbalance (particularly hypokalemia and metabolic acidosis), drowsiness, confusion, tinnitus, nausea, vomiting, and polyuria. Severe overdose can lead to convulsions, coma, and cardiovascular collapse. Treatment is primarily supportive and symptomatic, focusing on correction of electrolyte disturbances and acid-base balance. Hemodialysis may be effective in removing acetazolamide due to its low protein binding. There is no specific antidote.

Storage

Store at controlled room temperature (20°-25°C or 68°-77°F), in a tightly closed container, and protect from light and moisture. Keep out of reach of children and pets. Do not store in bathrooms or other areas with high humidity. Discard any unused medication after the expiration date. Do not flush medications down the toilet or pour them into a drain unless instructed to do so; consult a pharmacist on proper disposal methods.

Disclaimer

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or before starting any new treatment. Never disregard professional medical advice or delay in seeking it because of something you have read here. Dosage and indications may vary based on individual patient factors and current medical guidelines.

Reviews

Clinical studies and meta-analyses consistently demonstrate Diamox’s efficacy in reducing intraocular pressure by approximately 40-60% in glaucoma patients. For altitude sickness prophylaxis, systematic reviews confirm its superiority over placebo, with a number needed to treat (NNT) of approximately 3-4 for preventing AMS symptoms. Neurologists report its value as an adjunctive therapy in specific epilepsy syndromes. The most frequently noted drawback in patient-reported outcomes is the common occurrence of paresthesia and dysgeusia, though these are generally tolerable and dose-dependent. Its long-standing presence in formularies worldwide attests to its established risk-benefit profile when used appropriately under medical supervision.