Treatment of Opioid Dependence with Depot Buprenorphine (CAM2038) in Custodial Settings Is Safe, Effective and Cost-Effective

Background: Opioid agonist treatment (OAT) is effective but resource intensive to administer safely in custodial settings, leading to significant under-treatment of opioid dependence in these settings worldwide. Methods: This open-label trial compared depot buprenorphine, CAM2038 (weekly for 4 weeks then monthly) to oral methadone ( https://www.anzctr.org.au ACTRN12618000942257). Modelled treatment costs included a comparison group on sublingual buprenorphine-naloxone. Men and women, aged>18 years of various security classifications with a diagnosis of moderate to severe DSM-5 opioid use disorder and a custodial sentence of at least six months were recruited from correctional centres in New South Wales, Australia. Findings: Between November 2018 and July 2019, 67 patients not in OAT treatment at recruitment commenced depot buprenorphine. Sixty-two patients already stable on oral methadone treatment were recruited to the comparison arm. Patients treated with depot buprenorphine commonly reported at least one adverse event related to study drug (63/67, 94%), typically mild and transient. No diversion of depot buprenorphine was identified. Retention in depot buprenorphine treatment was 92%. Self-reported use of non-prescribed opioids (primarily buprenorphine-naloxone) and injecting drug use decreased significantly among depot buprenorphine patients by 16 weeks (p