What is the role of Diamox (acetazolamide) in treating glaucoma?

From the Guidelines

Diamox (acetazolamide) is not typically considered a first-line treatment for glaucoma, but rather as an adjunctive therapy or for acute angle-closure glaucoma emergencies. According to the most recent guidelines, prostaglandin analogs are the most frequently prescribed initial eye drops for lowering intraocular pressure (IOP) in patients with glaucoma due to their efficacy and tolerability 1. Diamox, as a carbonic anhydrase inhibitor, works by blocking the enzyme carbonic anhydrase in the ciliary epithelium, reducing bicarbonate and fluid formation in the eye, thereby lowering pressure.

Some key points to consider when using Diamox for glaucoma treatment include:

• Typical dosage: 250-500 mg orally twice daily for adults, or 500 mg extended-release capsule once daily
• Common side effects: tingling in extremities, altered taste, fatigue, and increased urination
• Contraindications: sulfa allergies, severe kidney or liver disease, and electrolyte imbalances
• Necessary monitoring: regular monitoring of electrolytes and kidney function, and maintaining adequate hydration to prevent kidney stone formation

It's essential to weigh the benefits and risks of Diamox treatment, considering the patient's individual needs and comorbidities, as outlined in the primary open-angle glaucoma preferred practice pattern guidelines 1. However, the most recent and highest quality study 1 suggests that other medications, such as prostaglandin analogs, are preferred as initial therapy due to their efficacy and tolerability.

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.

The role of Diamox (acetazolamide) in treating glaucoma is to decrease the secretion of aqueous humor, which results in a drop in intraocular pressure. This is a desirable reaction in cases of glaucoma. Key points include:

• Carbonic anhydrase inhibition: Acetazolamide acts as a potent inhibitor of this enzyme.
• Decreased aqueous humor secretion: This leads to a decrease in intraocular pressure.
• Utility in glaucoma treatment: Acetazolamide is considered effective in the control of fluid secretion in some types of glaucoma 2.

From the Research

Role of Diamox in Treating Glaucoma

• Diamox, also known as acetazolamide, is a carbonic anhydrase inhibitor used in the treatment of glaucoma to lower intraocular pressure (IOP) 3, 4.
• The medication works by reducing the production of aqueous humor in the eye, thereby decreasing IOP 3.
• Studies have shown that acetazolamide is effective in lowering IOP, with a substantial pressure-lowering effect that lasts at least 23 hours 3.
• The optimal dosage of acetazolamide for glaucoma treatment is still being researched, but it is known that a capsule taken once a day can offer a significant pressure-lowering effect, although the magnitude of the pressure lowering may be less than with higher dosages 3.

Efficacy and Safety of Diamox

• Oral acetazolamide is an efficacious adjunct to topical therapy for lowering IOP in glaucomatous eyes, but its use requires careful consideration of the benefits and risks 4.
• The benefits of oral carbonic anhydrase inhibitor therapy can outweigh the risks in many circumstances, but it is essential to monitor for and mitigate risks, such as allergy information and limited cross-reactivity between antimicrobial and non-antimicrobial sulfonamides 4.
• Acetazolamide is not often a first-line option for glaucoma treatment, but it remains a pivotal and important role in the delivery of eye care, particularly in cases where other treatments are contraindicated or ineffective 4, 5.

Treatment of Glaucoma

• The treatment of glaucoma is focused on lowering IOP with topical drugs, laser therapy, and glaucoma surgery 5.
• In patients with manifest glaucoma, lowering IOP prevents the progression of visual field defects, and individually tailored pressure-lowering treatment should be evaluated in regularly scheduled follow-up visits 5.
• Current primary open-angle glaucoma treatments include classes of drugs like prostaglandin analogs, beta-blockers, alpha-agonists, and carbonic anhydrase inhibitors, but new views have surfaced about other pathophysiological processes being involved in POAG progression, and adjunctive treatments are being researched 6.