Naturalistic follow-up after a trial of medications for opioid use disorder: Medication status, opioid use, and relapse

Aim: This report examined naturalistic opioid use outcomes and utilization of medications for opioid use disorder (MOUD) 36 weeks post-randomization in the National Drug Abuse Treatment Clinical Trials Network (CTN) Extended-Release Naltrexone (XR-NTX) versus Buprenorphine-Naloxone (BUP-NX) for Opioid Treatment trial (CTN-0051, X:BOT).

Design: X:BOT was a multisite, randomized, 24-week comparative effectiveness trial of BUP-NX (N = 287) and XR-NTX (N = 283). Study medications were discontinued following treatment completion, relapse, or dropout. Participants were encouraged to continue MOUD. This report examined opioid use outcomes in 428 (75%) of the 570 participants who attended the 36-week follow-up visit.

Setting and participants: Adults with opioid use disorder recruited from 8 community treatment programs across the United States.

Measurements: Outcomes included medication status (on/off MOUD), type of MOUD (BUP-NX, XR-NTX, or methadone), abstinence from non-prescribed opioids, opioid use days, relapse, and other substance use 30 days prior to the 36-week visit. Relapse was defined as opioid use for 4 consecutive weeks or 7 consecutive days in the past month. Baseline and clinical variables included opioid use severity, intravenous drug use, study medication assignment, and induction status.

Findings: Of the 428 participants who completed the 36-week visit, 225 (53%) of participants were receiving MOUD and 203 (47%) were not. Compared to those off medication, participants on medication had fewer opioid use days (4.4 days (SD 9.0) versus 9.8 days (SD 12.1)), fewer met relapse criteria (37 (16.4%) versus 79 (38.9%)), and reported less stimulant use (34 (15.2%) versus 56 (27.7%)) and sedative use (14 (6.3%) versus 31 (15.3%)). There was no difference in abstinence rates between those on or off MOUD. A greater proportion of participants on XR-NTX (47 (53.4%) of 88 participants) were abstinent from non-prescribed opioids compared to those on buprenorphine (28 (23.3%) of 120 participants).

Conclusions: Naturalistic outcomes data showed that despite potential barriers to continuing treatment in the community, about half of individuals were on opioid use disorder pharmacotherapy at follow-up and those on medication generally had better outcomes. Future research should explore barriers and facilitators to treatment retention in community settings; and developing interventions tailored to improve treatment engagement and adherence.