2024 Volume 13 Issue 2 Pages 201-205
We encountered a case in which acetazolamide (AZ), a renal excretory drug, tablets were set at a dose above the typical therapeutic range for the treatment of glaucoma in a hemodialysis (HD) patient, and blood levels and side effects were observed.
A woman in her 50s was undergoing HD and treated for right-angle-closure glaucoma secondary to diabetic retinopathy at an ophthalmology clinic. Multiple eye drops and AZ tablets were used to treat glaucoma, and AZ tablets of 125 mg thrice weekly resulted in a blood concentration of 14.3 µg/mL, which is within the therapeutic range (5–15 µg/mL). However, the ophthalmologist highlighted the elevated intraocular pressure to the attending dialysis physician and suggested increasing the AZ dose until glaucoma surgery was performed. The pharmacist explained the need to monitor for side effects, such as central nervous system (CNS) symptoms, hemopenia, and electrolyte abnormalities, which may occur because of increased blood AZ concentration associated with the increased dose, and the need to monitor blood AZ concentration, suggesting to increase the dose to 125 mg five times weekly. After increasing the dose, blood levels measured once a month remained above the therapeutic range at 21.2 μg/mL, 21.6 μg/mL, and 17.5 μg/mL, and increased intraocular pressure was suppressed. Subsequently, glaucoma surgery was performed and AZ tablets were discontinued because intraocular pressure improved. During the AZ dose escalation period, no hemopenia, electrolyte abnormalities, or CNS symptoms, such as convulsions and mental confusion, were observed.
Although the efficacy of high AZ concentrations in the treatment of glaucoma is unclear, this case shows that treatment could have been continued with the general dose regimen of AZ for HD patients and a theoretical dosing plan and observation of safety in collaboration with the ophthalmologist.
