Treatment with acetazolamide can improve symptoms of obstructive sleep apnea (OSA), according to a study presented at the 2023 American Thoracic Society International Conference in Washington, DC, May 19-24. found.1
Acetazolamide, a carbonic anhydrase inhibitor that stabilizes the respiratory drive, has been shown to reduce loop gain, a marker of respiratory control system stability. Although this marker is known to contribute to the pathophysiology of OSA, data regarding the efficacy and optimal dose of acetazolamide as a treatment are lacking.
Investigators are conducting a placebo-controlled, double-blind, parallel-group study to evaluate the efficacy and dose-dependent effects of acetazolamide in patients with OSA. This study cohort included 49 patients with confirmed moderate-to-severe OSA, 81.6% of whom were men aged 48 to 58.5 years with a BMI of 26.8 to 30.9.
Participants were randomized to three different treatment arms: placebo, 250 mg acetazolamide, and 500 mg acetazolamide. Each patient received the drug once daily for her 6 weeks. Changes in apnea hypopnea index (AHI) and oxygen desaturation index (ODI) were assessed using laboratory polysomnography. A questionnaire was used to assess side effects.
A total of 43 participants have completed the study to date. The researchers found that acetazolamide significantly lowered his AHI, improving by 34.6% after placebo correction and lowering his ODI by 53.5%. He had no significant difference in AHI between doses of acetazolamide. However, more side effects (mainly paresthesia) were reported at the 500mg dose.
“These findings demonstrate that acetazolamide can improve OSA,” the authors concluded. “Increased doses did not show further improvement in terms of AH or ODI reduction, but showed more side effects.”