title: Employment-based reinforcement of adherence to an FDA approved extended release formulation of naltrexone in opioid-dependent adults: a randomized controlled trial.
abstract: BACKGROUND
  Naltrexone provides excellent opioid blockade, but its clinical utility is limited because opioid-dependent patients typically refuse it. An injectable suspension of naltrexone for extended release (XR-NTX) was recently approved by the FDA for treatment of opioid dependence. XR-NTX treatment may require concurrent behavioral intervention to maximize adherence and effectiveness, thus we sought to evaluate employment-based reinforcement as a method of improving adherence to XR-NTX in opiate dependent adults.
  
  
  METHODS
  Opioid-dependent adults (n=38) were detoxified and inducted onto oral naltrexone, then randomly assigned to contingency or prescription conditions. Participants received up to six doses of XR-NTX at four-week intervals. All participants could earn vouchers for attendance and performance at a therapeutic workplace. Contingency participants were required to accept XR-NTX injections to access the workplace and earn vouchers. Prescription participants could earn vouchers independent of their acceptance of XR-NTX injections.
  
  
  RESULTS
  Contingency participants accepted significantly more naltrexone injections than prescription participants (87% versus 52%, p=.002), and were more likely to accept all injections (74% versus 26%, p=.004). Participants in the two conditions provided similar percentages of samples negative for opiates (72% versus 65%) and for cocaine (58% versus 54%). Opiate positivity was significantly more likely when samples were also cocaine positive, independent of naltrexone blockade (p=.002).
  
  
  CONCLUSIONS
  Long-term adherence to XR-NTX in unemployed opiate dependent adults is low under usual care conditions. Employment-based reinforcement can maintain adherence to XR-NTX. Ongoing cocaine use appears to interfere with the clinical effectiveness of XR-NTX on opiate use.
authors.affiliation: Johns Hopkins University, School of Medicine, Baltimore, MD 21224, United States.
authors.forename: Anthony
authors.initials: A
authors.lastname: DeFulio
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Everly
authors.forename: Jeannie-Marie S
authors.initials: JM
authors.lastname: Leoutsakos
authors.forename: Annie
authors.initials: A
authors.lastname: Umbricht
authors.forename: Michael
authors.initials: M
authors.lastname: Fingerhood
authors.forename: George E
authors.initials: GE
authors.lastname: Bigelow
authors.forename: Kenneth
authors.initials: K
authors.lastname: Silverman
mesh_terms: D000328:Adult; D003692:Delayed-Action Preparations; D004651:Employment; D005260:Female; D006801:Humans; D008297:Male; D055118:Medication Adherence / Q000523:psychology; D008875:Middle Aged; D009271:Naltrexone / Q000008:administration & dosage* / Q000627:therapeutic use; D009292:Narcotic Antagonists / Q000008:administration & dosage* / Q000627:therapeutic use; D009293:Opioid-Related Disorders / Q000188:drug therapy* / Q000523:psychology; D012054:Reinforcement, Psychology; D017132:Workplace
chemical_list: D003692:Delayed-Action Preparations; D009292:Narcotic Antagonists; D009271:Naltrexone