Patient-centered and Neurocognitive Outcomes With Acetazolamide for Sleep Apnea

The goal of this randomized, controlled, double-blind clinical trial is to compare the medication acetazolamide 500mg/day against placebo in adults who have at least moderate severe obstructive sleep apnea. The main questions this trial aims to answer are: Is acetazolamide for 4 weeks more effective than placebo for treating obstructive sleep apnea? Is acetazolamide for 4 weeks more effective than placebo for improving neurocognitive function and quality of life? What are potential predictors and mechanisms of improvements with acetazolamide in sleep apnea, neurocognitive function and quality of life? Participants will undergo the following activities: * Eligibility screening (online or via phone; \~10min) * Subjects who screen positive: in-person eligibility assessment (\~1h) including a history, exam, blood testing, plus an overnight home sleep test * Participants who are eligible: will come to the research lab (\~15min) and be provided with a 4-week supply of the first study drug (i.e. acetazolamide or placebo) to be taken each night at home. Neither the researchers, nor the participants will know whether participants received acetazolamide or placebo. During this 4-week period, participants will wear a watch-sized activity tracker to measure their sleep amount and researchers will check in on participants weekly; at the end of the 4-week period participants are asked to come in for an overnight visit (\~12h) which includes the following activities: general exam, questionnaires (e.g. quality of life), blood test, neurocognitive function tests, and an overnight sleep study to assess the severity of sleep apnea Researchers will compare the effects of acetazolamide on sleep apnea severity, neurocognitive function and quality of life with the effects of placebo to see if acetazolamide may be an effective treatment for select patients with sleep apnea.