Extended-release naltrexone (XR-NTX) for opioid use disorder in clinical practice: Vivitrol's Cost and Treatment Outcomes Registry

Background and Aims Extended-release naltrexone (XR-NTX), a mu-opioid receptor antagonist for prevention of relapse to opioid dependence, has demonstrated efficacy compared with placebo and comparative effectiveness with buprenorphine-naloxone. We report outcomes for XR-NTX in Vivitrol's Cost and Treatment Outcomes Registry. Design Observational, open-label, single-arm, multi-center registry assessing baseline characteristics and clinical and health-related quality-of-life outcomes associated with XR-NTX treatment in clinical practice. Setting 32 US treatment centers from 2011 to 2013. Participants Patients with opioid dependence who were prescribed XR-NTX treatment and then enrolled into the registry. Measurements Monthly visits were evaluated for the full population and for patient ubgroups retrospectively, defined by injection number, focusing on the period between baseline and month 6 (1-, 2/3- or 6-XR-NTX). Findings Of 403 enrolled patients, 395 were analyzed. Most patients (n=349) received out-patient care. On average, patients received five injections (median=3; range=1-25). The median number of injections administered within 6 months was higher in patients who at baseline were employed (three versus two unemployed, P=0.02) or had private insurance (five versus two self-payment, P=0.005; versus two state-funded, P<0.001). The 1-, 2/3- and 6-XR-NTX groups had 132, 152 and 111 patients, respectively. At baseline, the 6-XR-NTX patients were more likely to meet normal/minimal mental illness criteria and attend school and less likely to report recent drug use. Within 6 months, the 6-XR-NTX group demonstrated improvements in employment, mental health and psychosocial functioning, and decreases in opioid craving, drug use and drug-related behavior. Conclusions Among opioid-dependent people receiving XR-NTX treatment, better mental health, higher education and lower recent drug use at baseline are associated with greater treatment duration; in turn, longer treatment duration is associated with lower relapse rates and improved outcomes generally.