Long-term follow-up study of community-based patients receiving XR-NTX for opioid use disorders.

BACKGROUND AND OBJECTIVES: Extended-release naltrexone (XR-NTX) is FDA-approved to prevent relapse in patients with Opioid Use Disorder. However little is known about long-term use among community-based outpatients.

METHODS: Retrospective chart review and long-term follow-up survey among individuals (N = 168) who entered an outpatient XR-NTX trial between 2011 and 2015, during which participants were offered three monthly injections of XR-NTX at no cost. The survey consisted of 35 questions covering a total of four domains: (1) substance use; (2) treatment continuation; (3) barriers; and (4) attitudes.

RESULTS: Fifty-seven respondents were successfully surveyed, including 50% of those initially receiving all three XR-NTX injections ("study completers") in the parent study. Study completion was associated with superior outcomes and less likely relapse (defined as daily use), with a much greater time to relapse despite higher rates of concurrent non-opioid substance use. However the majority of participants discontinued treatment with XR-NTX at study completion, largely due to attitudes of "feeling cured" and "wanting to do it on my own" rather than external barriers such as cost or side effects.

CONCLUSION: Patients who initiate treatment with XR-NTX might benefit from anticipatory guidance and motivational techniques to encourage long-term adherence as many will experience internal barriers to continuation. Our findings are reassuring that few patients experience side effects or adverse events complicating the effectiveness or safety of long-term use of XR-NTX.

SCIENTIFIC SIGNIFICANCE: Among outpatients who successfully receive 3 monthly XR-NTX injections, many will prematurely discontinue treatment due to internal attitudes, such as "feeling cured." (Am J Addict 2017;26:319-325).