Is extended release naltrexone superior to buprenorphine-naloxone to reduce drinking among outpatients receiving treatment for opioid use disorder? A secondary analysis of the CTN X:BOT trial.
The randomized X:BOT trial (CTN-0051) showed that following induction, sublingual agonist (buprenorphine-naloxone, BUP-NX) or antagonist injection (extended release naltrexone, XR-NTX) produced similar benefits for reducing opioid relapse in injection users with opioid use disorder. Given that XR-NTX reduces drinking in alcohol use disorder (AUD), researchers completed a secondary analysis of the X:BOT sample of patients successfully inducted onto treatment to determine if XR-NTX (n=204) was superior to BUP-NX (n=270) to reduce drinking or heavy drinking in patients with opioid use disorder.
Researchers examined timeline follow-back recorded standard drink units consumed and used mixed-models regression to analyze monthly frequencies of any drinking or heavy drinking over 6 months of treatment and proportional hazard survival examined time to first drink.
Both treatment groups reduced drinking from baseline to post-treatment (small to medium effect), but no differences between groups were detected. However, only 29% (n=136) of the sample had AUD and 19% (n=26/136) of those were abstinent before treatment. Analysis of a subsample enriched for possible drinking included n=136 with an AUD diagnosis plus n=43 who did not have AUD, but reported at least one day of heavy drinking prior to study. Even so, this subsample still reported only 32% of days of any drinking with a median of only 13% of days designated as “heavy”. Within this subsample, the BUP-NX group reported greater mean drinks per drinking day than did the XR-NTX group at baseline (p=0.03); however, there were no other significant group differences in drinking observed before, during, or at the end of treatment.
Conclusions: An overall improvement in drinking occurred for treatment of OUD using both agonist and antagonist approaches indicating that the hypothesis that XR-NTX would be superior to BUP-NX was not supported. The study is limited by low levels of comorbid AUD or heavy drinking observed in X:BOT trial participants seeking treatment for opioid use disorder.
Related protocols: CTN-0051