STASH, Vol. 13(12) – Comparing naltrexone and buprenorphine-naloxone: Which reduces opioid relapse?

To prevent opioid relapse, doctors can turn to medication assisted treatment (MAT), which often includes combining counseling with medications such as methadone, Buprenorphine, or extended-release naltrexone. Previous research with criminal justice offenders has shown extended release naltrexone to reduce relapse by about 30%. However, little is known about how extended release naltrexone, a newer form of treatment, compared to more traditional forms of treatment, such as Buprenorphine for opioid relapse prevention within the general population. This week’s STASH reviews a study by Dr. Joshua Lee and his colleagues that assessed the effectiveness of both extended-release naltrexone and Buprenorphine-naloxone for opioid relapse.

What was the research question?

Which is more effective for opioid relapse prevention: extended-release naltrexone or Buprenorphine-naloxone?

What did the researchers do?

During a 24 week study period, the researchers conducted an open-label randomized controlled trial at 8 community treatment programs. The study included 570 adults who had used opioids in the past month and met DSM-V diagnostic criteria for an opioid use disorder. To study effectiveness, the researchers assessed if participants successfully completed the induction phase of treatment (i.e., the beginning of medication-assisted treatment after withdrawal and before the maintenance phase) and if participants experienced a relapse during the 24 week study period.

What did they find?

As displayed in Figure 1, Lee and his colleagues found that participants in the extended-release naltrexone group had a harder time completing the induction phase of treatment compared to Buprenorphine-naloxone. 72% of participants in the extended-release naltrexone group completed induction, compared to 94% in the Buprenorphine-naloxone group. In addition, participants in the extended-release naltrexone treatment group were also approximately 44% more likely to experience a relapse compared to those being treated with Buprenorphine-naloxone generally. Lee and his colleagues reported that most of that difference was due to relapse during the induction phase of treatment.

Figure. Percentage of treatment seekers for an opioid use disorder who successfully completed the induction phase of treatment by medication type, adapted from Lee et al., 2017.  Click image to enlarge.

Why do these findings matter?

These findings indicate a need for treatment providers in community settings to better support induction among patients using extended-release naltrexone to treat an opioid use disorder. This might explain why previous studies have shown positive results with extended-release naltrexone in controlled settings. Those seeking help for an opioid use disorder outside of controlled settings should consider medication-assisted treatment with Buprenorphine-naloxone.

Every study has limitations. What are the limitations in this study?

Both treatment providers and treatment seekers were aware of the medications they were taking, which might introduce bias into the results. The authors note that the varied induction protocols at the treatment centers might have had a substantial effect on participants successful induction with extended-release naltrexone. This methodological challenge limits our ability to interpret the findings. Finally, the acute detoxification setting limits our ability to generalize this study’s findings to other types of treatment centers.

For more information:

If you are concerned about yours or a loved one’s substance use, visit our resource page for brief screens to assess substance use and self-help tools.

— John H. Kleschinsky

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