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 μ-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.