The aim of this study was to investigate the acceptability of methadone-naloxone through interviews with potential consumers and treatment providers about their attitudes and beliefs about combining methadone with naloxone. A qualitative study was conducted with structured surveys and individual interviews with nine consumers and 11 treatment providers. Results indicate that fear and issues around trust were identified as barriers to consumer acceptance of methadone-naloxone. Respect for the choices that consumers made about their treatment and drug use, and clear and open communication were identified as necessary to win consumer acceptance. Both groups had concerns about the safety and efficacy of methadone-naloxone compared with methadone, but also most identified potential benefits from a new opioid treatment option. For both groups, the acceptability of methadone-naloxone depended upon an informed assessment of risks and benefits best addressed by further research into the efficacy, tolerability, and safety of methadone-naloxone. References (Published Abstract)