Preventing prescription opioid poisoning deaths is a major public health priority in Western societies. Deaths from these medications exceed deaths from all illicit drugs combined [1]. Methadone (for pain treatment) is involved in one third of US prescription opioid overdose deaths despite accounting for only 5% of dispensed opioids [2]. There is a dose-dependent increase in the severity of central sleep apnoea (CSA) with methadone [3–5] and sleep disordered breathing is a contributing factor in methadone-related deaths [2]. The partial μ-agonist buprenorphine is putatively safer than methadone with a ceiling effect upon respiratory depression [6]. However, the effect of buprenorphine on breathing during sleep remains unclear. The only relevant report from a cross-sectional observ…