title: Do patient characteristics moderate the effect of extended-release naltrexone (XR-NTX) for opioid use disorder?
abstract: Extended release naltrexone (XR-NTX) injected intramuscularly monthly has been shown to reduce relapse in persons with opioid use disorder. Baseline factors, including patients' demographics, comorbidities and lifestyle, may help identify patients who will benefit most or least from XR-NTX treatment.
  
  
  
  Potential moderators of XR-NTX's effect were examined in the largest North American randomized open-label effectiveness trial of XR-NTX. Relapse status (Yes/No) at 6-month follow-up was regressed on treatment group (XR-NTX, N=153; or Treatment-as-Usual [TAU], N=155), baseline covariates, and their two-way interaction to identify moderator effects. Baseline covariates included age, gender, summary scores for depression, suicidal thoughts, drug abuse risk, substance use, medical, psychiatric and employment status, socialization, legal and family/social issues, history of abuse and quality of life measures.
  
  
  
  Alcohol use to intoxication in the 30days before randomization was a significant moderator: during the treatment phase, those who reported being recently intoxicated before randomization to XR-NTX relapsed to opioids at a rate (56%) similar to TAU (58%), while those without alcohol intoxication in the prior 30days had a lower rate of opioid relapse (41% vs. 65%, respectively, P<0.04).
  
  
  
  XR-NTX appeared to work equally well across subgroups with diverse demographic, addiction, mental health and environmental characteristics, with the possible exception of working better among those without recent alcohol intoxication. These findings should be reassuring to practitioners increasingly using XR-NTX as medical addiction therapy in diverse and often vulnerable populations.
authors.affiliation: Office of Research, Department of Medicine, University of Massachusetts-Baystate and Baystate Health, Springfield, MA, United States. Electronic address: Peter.friedmannmd@baystatehealth.org.
authors.forename: Peter D
authors.initials: PD
authors.lastname: Friedmann
authors.affiliation: Office of Research, Department of Medicine, University of Massachusetts-Baystate and Baystate Health, Springfield, MA, United States.
authors.forename: Donna
authors.initials: D
authors.lastname: Wilson
authors.affiliation: New York State Psychiatric Institute, Columbia University Medical Center, New York, NY, United States.
authors.forename: Edward V
authors.initials: EV
authors.lastname: Nunes
authors.affiliation: Office of Research, Department of Medicine, University of Massachusetts-Baystate and Baystate Health, Springfield, MA, United States.
authors.forename: Randall
authors.initials: R
authors.lastname: Hoskinson
authors.affiliation: Department of Population Health, New York University School of Medicine, New York, United States.
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Lee
authors.affiliation: Friends Research Institute, Baltimore, MD, United States.
authors.forename: Michael
authors.initials: M
authors.lastname: Gordon
authors.affiliation: Department of Health Policy and Administration, Washington State University, Spokane, WA, United States.
authors.forename: Sean M
authors.initials: SM
authors.lastname: Murphy
authors.affiliation: University of Virginia School of Law, Charlottesville, VA, United States.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Bonnie
authors.affiliation: Center for Biomedical Ethics and Humanities, Departments of Public Health Sciences and Psychiatry and Neurobehavioral Sciences, University of Virginia School of Medicine, Charlottesville, VA, United States.
authors.forename: Donna T
authors.initials: DT
authors.lastname: Chen
authors.affiliation: Treatment Research Institute, University of Pennsylvania, Philadelphia, PA, United States.
authors.forename: Tamara Y
authors.initials: TY
authors.lastname: Boney
authors.affiliation: Treatment Research Institute, University of Pennsylvania, Philadelphia, PA, United States.
authors.forename: Charles P
authors.initials: CP
authors.lastname: O'Brien
mesh_terms: D000328:Adult; D000435:Alcoholic Intoxication / Q000150:complications; D003692:Delayed-Action Preparations; D005260:Female; D006801:Humans; D007273:Injections, Intramuscular; D008297:Male; D009271:Naltrexone / Q000008:administration & dosage*; D009292:Narcotic Antagonists / Q000008:administration & dosage*; D009293:Opioid-Related Disorders / Q000188:drug therapy*; D011788:Quality of Life; D055502:Secondary Prevention; D013997:Time Factors
chemical_list: D003692:Delayed-Action Preparations; D009292:Narcotic Antagonists; D009271:Naltrexone