1325 Severe Central Sleep Apnea and Sleep-Related Hypoventilation in a Patient on Buprenorphine/Naloxone

Abstract Introduction Opioid substitution therapy (OST) is a recognized risk factor for central sleep apnea (CSA) and sleep-related hypoventilation. While methadone has been strongly associated with severe sleep-disordered breathing, buprenorphine is often regarded as a safer alternative. However, the impact of dosing timing and residual ventilatory impairment remains incompletely understood. Report of case(s) A 49-year-old male with opioid use disorder in sustained remission on buprenorphine/naloxone presented with excessive daytime sleepiness and self-initiated CPAP use without prior diagnostic testing. Polysomnography demonstrated severe mixed sleep-disordered breathing with predominant central apneas, nocturnal bradypnea, and hypercapnia. PAP titration revealed CPAP failure due to the emergence of central apneas, with partial improvement on BiPAP-ST. Conclusion While evening methadone dosing has been associated with increased sleep-disordered breathing and no significant correlation between buprenorphine dose and AHI in prior studies, data specific to buprenorphine dosing and timing remain limited. This case highlights that while buprenorphine may reduce CSA severity compared to full opioid agonists, clinically significant central apnea and hypoventilation may persist, potentially influenced by dosing timing and impaired chemosensitivity. Support (if any)