From the Guidelines
Acetazolamide can cause several eye-related side effects, including transient myopia, angle-closure glaucoma, and visual field defects, and patients should be monitored closely for these adverse effects, particularly those with pre-existing eye conditions 1. The most common ocular side effects of acetazolamide include:
- Transient myopia (nearsightedness)
- Angle-closure glaucoma
- Visual field defects Patients may experience blurred vision, eye pain, or changes in color perception.
Management of Eye Side Effects
Myopia typically resolves upon discontinuation of the medication. For angle-closure glaucoma, immediate ophthalmologic consultation is necessary, and the drug should be discontinued. Management may include:
- Topical beta-blockers like timolol 0.5% drops
- Topical alpha-2 agonists such as brimonidine 0.2%
- Oral osmotic agents like mannitol to reduce intraocular pressure Some patients develop ocular hypersensitivity reactions requiring steroid eye drops. Regular eye examinations are recommended for patients on long-term acetazolamide therapy, particularly those with pre-existing eye conditions. These side effects occur because acetazolamide inhibits carbonic anhydrase in ocular tissues, altering fluid dynamics within the eye and potentially causing changes in lens thickness and position. Patients should be instructed to report any visual disturbances immediately, as prompt intervention can prevent permanent vision loss. In cases of severe reactions, alternative medications such as topiramate or furosemide may be considered depending on the clinical indication, as suggested by the most recent guidelines on idiopathic intracranial hypertension management 1. It is essential to weigh the benefits and risks of acetazolamide therapy, considering the potential for eye-related side effects, and to closely monitor patients for any adverse effects, as recommended in the primary open-angle glaucoma suspect preferred practice pattern 1.
From the FDA Drug Label
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 potential eye side effects of Acetazolamide include a decrease in intraocular pressure, which can be beneficial in cases of glaucoma.
- The mechanism of action involves the inhibition of carbonic anhydrase in the eye, leading to a decrease in the secretion of aqueous humor.
- This decrease in intraocular pressure can be desirable in certain non-glaucomatous conditions as well. Management of these eye side effects is not explicitly stated in the provided drug label, but it can be inferred that monitoring of intraocular pressure may be necessary in patients taking Acetazolamide, especially those with pre-existing glaucoma or other eye conditions 2.
From the Research
Potential Eye Side Effects of Acetazolamide
The potential eye side effects of Acetazolamide, a carbonic anhydrase inhibitor, include:
- Myopia [@\5@]
- Bilateral choroidal effusions [@\5@]
- Blurred vision [@\2@]
- Ocular discomfort [@\2@]
- Abnormal taste [@\2@]
Management of Eye Side Effects
Management of eye side effects associated with Acetazolamide involves:
- Monitoring of erythrocyte acetazolamide concentration and plasma chloride ion to prevent overdosage and side effects [@\1@]
- Adjusting the dose of Acetazolamide to minimize side effects [@\3@]
- Considering alternative treatments, such as topical carbonic anhydrase inhibitors, which may have a lower risk of systemic side effects [@\2@]
- Collaboration between eye care practitioners and primary care practitioners to monitor for and mitigate risks [@\4@]
Dose Dependence of Side Effects
The risk of certain side effects, such as paraesthesias and dysgeusia, has been shown to increase with higher doses of Acetazolamide [@\3@]
- The numbers needed to harm for each of these side effects are:
- Paraesthesias: 2.3 (95% CI 2 to 2.7) [@\3@]
- Dysgeusia: 18 (95% CI 10 to 38) [@\3@]
- The risk of fatigue also increases with higher dose, but not significantly [@\3@]