In British Columbia, individuals suffering from opioid use disorder who were treated with methadone exhibited a 37-40% reduced likelihood of stopping treatment compared to those using buprenorphine/naloxone.
This recent research, released in the Journal of the American Medical Association, explored the rates of treatment discontinuation and mortality among patients receiving opioid agonist therapy (OAT) over a 10-year span.
“Decreasing treatment discontinuation rates is crucial for saving lives. With the significant loss of life attributed to fentanyl in B.C.’s unregulated drug market, it’s essential to continue assessing our best treatment alternatives,” remarked Dr. Bohdan Nosyk, a scientist at the Centre for Advancing Health Outcomes and a professor at Simon Fraser University’s Faculty of Health Sciences. “Studies like this that utilize high-quality health administrative data provide valuable insights into the effectiveness of our treatment methods amidst a changing toxic drug supply.”
The investigation, titled “Buprenorphine/naloxone versus methadone for the treatment of opioid use disorder,” was the result of cooperation among researchers and public health experts from the Centre for Advancing Health Outcomes, Simon Fraser University, BC Centre on Substance Use, University of British Columbia (UBC), and McGill University, alongside institutions in the UK, Austria, and various US universities.
The study encompassed all individuals in B.C. who were prescribed either methadone or buprenorphine/naloxone for opioid use disorders between January 1, 2010, and March 17, 2020—with a total of 30,891 participants. It compared the effects of these medications on treatment retention and overall mortality rates. Fentanyl was first spotted in the drug supply in 2012 and became the main cause of overdose deaths in 2016. The research timeframe concluded just before the province announced a public health emergency due to COVID-19. Notably, over 61% of participants in the study were on methadone.
The findings indicated that individuals on methadone had a lower risk of discontinuing treatment when compared to those using buprenorphine/naloxone. While mortality rates during treatment remained low for both groups and showed no significant differences (0.13% for methadone vs. 0.08% for buprenorphine/naloxone), these results persisted even after fentanyl’s introduction and across various patient demographics, including young adults under 24, those with severe mental health issues, and individuals with chronic pain.
“The advantages of these treatments can only be realized while patients remain on them. However, retention rates in OAT have been steadily declining over the last 13 years,” stated Dr. Paxton Bach, a Clinical Assistant Professor in UBC’s Department of Medicine, Co-Medical Director for the BC Centre on Substance Use, and a co-author of the study. “Ongoing assessment and enhancement of clinical guidelines based on the best existing evidence is essential to provide optimal support for individuals with opioid use disorder in B.C. and beyond.”
Previous studies have shown that the risk of mortality for individuals on OAT more than doubles after they stop treatment compared to when they are actively receiving it.
The researchers highlighted that while this evidence underscores methadone as a well-supported treatment option, choices regarding medications should be made collaboratively with patients. Additionally, exploring new treatment strategies, such as the co-prescription of hydromorphone, is critical. It’s also vital to address existing barriers to treatment retention like urine drug testing and daily witnessed dosing, as well as to incorporate strategies to bolster retention, such as engaging peer support workers.
This study was funded by the Health Canada Substance Use and Addictions Program and the National Institute on Drug Abuse of the National Institutes of Health. The authors are solely responsible for the content, which may not represent the official views of the funding agencies.
Background
- British Columbia has experienced a swift increase in fentanyl use among individuals with opioid use disorder since it was first noted in coroner’s records in 2012. Fentanyl and its variants have been found in over 82% of drug overdose fatalities in B.C. every year since 2017.
- As reported by the BC Coroners Service, approximately six individuals die each day due to unregulated drug use.
- Both buprenorphine/naloxone and methadone are accessible in specialized drug treatment centers as well as office-based settings throughout B.C.
- This research utilized anonymized health administrative records, meaning individuals accessing OAT were not identified by name, and the outcomes were evaluated based on healthcare system interactions.
