Patients with chronic pain who use opioids appear to be at increased risk for breathing issues during sleep, termed sleep disordered breathing (SDB). Treatment of SDB often consists of use of a device during sleep that provides continuous positive airway pressure (CPAP) via a mask interface. However, this device is not effective or tolerated in all individuals. The goal of this study is to examine whether a medication called acetazolamide can improve SDB, as an alternative to CPAP treatment. The investigators will measure the improvement in SDB, as well as any change in symptoms, during a 1 week treatment with acetazolamide compared with 1 week of placebo (sugar pill). This study will help to provide data for longer term studies of treatment for SDB in patients who use opioids.