Employment-based reinforcement of adherence to oral naltrexone treatment in unemployed injection drug users.

Abstract

Naltrexone has high potential for use as a relapse prevention pharmacotherapy for opiate dependence; however suffers from notoriously poor adherence when prescribed for oral self-administration. This study evaluated whether entry to a therapeutic workplace could be used to reinforce adherence with oral naltrexone. Opiate-dependent and cocaine-using injection drug users were detoxified, inducted onto oral naltrexone, and randomly assigned to a Contingency (n=35) or Prescription (n=32) group for a 26-week period. Contingency participants were required to ingest naltrexone under staff observation to gain access to the therapeutic workplace. Prescription participants received a take-home supply of naltrexone and could access the workplace independent of naltrexone ingestion. Primary outcome measures were percent of urine samples positive for naltrexone at 30-day assessments and negative for opiates and cocaine at 30-day assessments. Contingency participants provided significantly more urine samples that were positive for naltrexone compared to Prescription participants (72% vs. 21%, P<.01), however no effect of experimental group was observed on percent opiate-negative (71% vs. 60%, P=.19.) or cocaine-negative (56% vs. 53%, P=.82) samples in the Contingency and Prescription groups, respectively. Opiate-positive samples were significantly more likely to occur in conjunction with cocaine (P<.001), and when not protected by naltrexone (P<.02), independent of experimental group. Overall, these results show that contingent access to a therapeutic workplace significantly promoted adherence to oral naltrexone, and that the majority of opiate use occurred in conjunction with cocaine use, suggesting that untreated cocaine use may limit the effectiveness of oral naltrexone in promoting opiate abstinence.

Effects of Acute Oral Naltrexone on the Subjective and Physiological Effects of Oral D-Amphetamine and Smoked Cocaine in Cocaine Abusers

“…Some studies suggest that NTX may be useful for treating COC abuse (Kosten et al, 1989;McCaul and Svikis, 1996;Oslin et al, 1999;Schmitz et al, 2001;Comer et al, 2006) and others do not (Hersh et al, 1998;Schmitz et al, 2009;DeFulio et al, 2012;Dunn et al, 2012). In humans seeking treatment for COC dependence, NTX significantly increased the percentage of COC-negative urines among patients receiving 50 mg NTX plus relapse prevention therapy relative to those receiving 0 mg NTX plus relapse prevention, and those receiving 0 mg or 50 mg NTX plus drug counseling (Schmitz et al, 2001).…”

Employment-based reinforcement of adherence to oral naltrexone in unemployed injection drug users: 12-month outcomes.

“…We recently conducted a study to evaluate a 26-week employment-based reinforcement intervention of oral naltrexone in unemployed injection drug users (Dunn et al, 2013). Participants were randomly assigned into a Contingency (n=35) group required to ingest naltrexone under staff observation to gain entry into a therapeutic workplace, or a Prescription (n=32) group given a take-home supply of oral naltrexone and access to the workplace without observed ingestion.…”

Employment-based abstinence reinforcement following inpatient detoxification in HIV-positive opioid and/or cocaine-dependent patients.

“…For instance, all the preceding studies that have been conducted in the Therapeutic Workplace with opiate-dependent patients enrolled individuals who were receiving either methadone (Silverman et al, 2001; Silverman et al, 2002) or naltrexone (DeFulio et al, 2012; Dunn et al, 2013; Everly et al, 2011) to manage their opiate dependence. The successful results of these studies are consistent with a recent meta-analysis that reported opiate detoxification is most successful when a combination of pharmacological and psychosocial support is provided (Amato et al, 2011).…”

“…Three studies inducted recently detoxified opioid-dependent patients onto oral naltrexone and then randomly assigned participants either to a contingency group that was required to accept oral naltrexone (Dunn et al, 2013), or a 6-dose course of sustained release naltrexone administered every 3 (Everly et al, 2011) or 4 (DeFulio et al, 2012) weeks to enter the workplace, or to a usual care condition that had access to the naltrexone product but could enter the workplace independent of naltrexone adherence. Results of all three studies showed improved adherence to naltrexone dosing in contingency versus control participants.…”