Adherence to extended release naltrexone: Patient and treatment characteristics.

Background And Objectives: Despite the promise of extended release naltrexone in the treatment of the opioid and alcohol use disorders, challenges with initiation and subsequent adherence have limited its potential. The purpose of this study is to identify the patient and treatment characteristics associated with adherence to extended release naltrexone.

Methods: Retrospective cohort study of 155 veterans who initiated the medication in FY 2014 and FY2015. Medical records were abstracted for patient and treatment data including preferred drug and utilization of substance use treatment in the year before and after medication initiation.

Results: Sample characteristics include 94% male, 70% domiciled, 60% without current legal problems, 30% employed, and preferred drug being opioids for 55% and alcohol for 45%. The mean of five extended release naltrexone injections did not differ by preferred drug. Treatment variables associated with medication adherence included concurrent substance use residential, individual, group, and psychiatric therapies (all p < .05) with inpatient detoxification admissions halved afterward (p < .0001) .

Discussion And Conclusions: Whereas most studies of extended release naltrexone have focused on patients with either alcohol or opioid use disorders for 6 months, this study allowed for a direct comparison of adherence in both groups over a year. The average treatment persistence in this veteran sample is greater than described in other public sector studies and may illustrate the importance of concurrent psychosocial therapies.

Scientific Significance: Results extend the findings of other studies and add to an emerging appreciation of the factors associated with treatment retention for extended release naltrexone. (Am J Addict 2018;27:524-530).