Initiation of extended release naltrexone (XR-NTX) for opioid use disorder prior to release from prison

Opioid use disorder is common in prison populations, and prison release is a high-risk time for relapse and overdose. Initiation of extended release injectable naltrexone (XR-NTX)) prior to prison release might decrease relapse among opioid-dependent persons.

This pilot study examined the feasibility and acceptability of XR-NTX injection prior to prison release among adult inmates with opioid use disorder, followed by six months of community XR-NTX treatment. It sought to determine effects on treatment retention and abstinence compared to post-release XR-NTX initiation.

Recruitment for the study took place at the RIDOC's Adult Correctional Institute (ACI). Volunteers with a history of opioid dependence and a release date scheduled within 1-2months were self-referred in response to recruitment fliers. Consented volunteers were randomized to XR-NTX treatment prior to release followed by 5 monthly treatments in the community (pre-release) or six XR-NTX treatments in the community (post-release).

Of 26 volunteers consented, 15 were randomized (9 pre-release, 6 post-release). The pre-release group generally had better treatment retention: 100% received the first NTX injection (vs. 67% post-release), 78% received more than one injection (vs. 17%) and 22% received all 6 injections (vs. 0%). The pre-release group also had greater abstinence, with a higher proportion of self-reported opioid free days in the first month after release (83% vs. 46%, fewer positive urine drug tests in the 6months after release (22% vs. 33%), and more days of opioid receptor blockade during the first two weeks after release, a high risk time for overdose death.

Initiation of XR-NTX injection prior to release from prison might be an effective approach to reduce relapse to opioids, but these findings require confirmation in a larger trial.