Comparing deaths associated with methadone and buprenorphine treatment

  • Ms Bethany Butler, The University of New South Wales, Australia
  • A/Prof James Bell, The Langton Centre, Australia
  • Dr Lieu Trinh, Centre for Health Services Research, Australia
  • Ms Anne Lawrance, NSW Health, Australia
  • Prof Robert Batey, NSW Health, Australia
  • Prof George Rubin, The Langton Centre, Australia

    • Aim: To compare mortality associated with methadone and buprenorphine treatment.
    Data Sources: The Opioid Treatment Program (OTP) database records start and end dates of all episodes of methadone and buprenorphine treatment in NSW, and the National Death Index (NDI) records all reported deaths. Division of Analytical Laboratories has tested for methadone and buprenorphine since 2006. Clinic records were used to identify dose levels and attendance among subjects who died while in treatment.
    Methods: This study builds on a prior study of retention in treatment of a large cohort entering their first episode of either methadone or buprenorphine treatment. To consider mortality among people entering treatment, names of people from that cohort were cross checked against the NDI database. Deaths were classified as occurring during induction (the two week period after commencing an episode of treatment), during subsequent maintenance, or out of treatment. We compared death risk during induction, and the mortality rate during and post the two forms of treatment. To assess diversion deaths, we investigated all post-mortem cases from 2007 in which methadone or buprenorphine was detected.
    Results: Among the 3513 people commencing buprenorphine, and 2646 people entering methadone treatment, 132 deaths were identified; 67 in the buprenorphine cohort and 65 in the methadone cohort. There were 2 deaths in 7,421 buprenorphine inductions, and 7 deaths in 4672 methadone inductions (RR=0.18, 95%CI [0.04-0.89], p=0.0335). Excluding the induction period, for people in both treatments, risk of death was significantly lower in treatment than out of treatment (RR=0.354, 95%CI=0.222-0.547, p<0.001). Mortality during the two treatments did not differ significantly. Diversion related deaths were still being analysed at the time of writing.
    Conclusions: Mortality in the two cohorts was very similar. Methadone and buprenorphine treatment are both effective in reducing the high mortality associated with opioid dependence. Buprenorphine is safer during induction.