The Comparative Effects of Buprenorphine and Methadone on Mortality
Opioid agonist treatment (OAT) with buprenorphine or methadone has been shown to have many benefits, including reducing mortality. However, relatively little is known about the comparative effects of these two agents. Researchers in the UK used data from primary care practices and national statistics to investigate the association between treatment with buprenorphine and methadone, and mortality. Treatment episodes were divided into 4 periods: 1) weeks 1–4 of OAT, 2) rest of time receiving OAT, 3) weeks 1–4 off OAT, 4) rest of time off OAT (up to 12 months).
- From 1998–2014, there were 11,033 people prescribed buprenorphine or methadone. The mean (and median) treatment duration was 363 (111) days for methadone and 173 (40) for buprenorphine; the mean daily dose was 65 mg for methadone and 8 mg for buprenorphine.
- There were 1.93 deaths/100 person-years while receiving OAT or within 12 months of cessation. Mortality was lowest from 4 weeks receiving OAT until cessation (0.98 deaths/100 person-years). Compared with receiving OAT, the adjusted mortality risk was 3.3 during weeks 1-4 of OAT, 10.4 weeks 1-4 off OAT, and 2.8 the rest of the time off OAT.
- Patients receiving buprenorphine had a lower mortality (unadjusted and adjusted) than those receiving methadone during each time period, particularly during weeks 1-4.
Comments: While some of these findings may be specific to practices in the UK, the most important messages are that OAT reduces mortality and that the initial period off of treatment is particularly dangerous. Buprenorphine may have some advantages, especially during treatment initiation, but this may be offset by shorter duration of treatment. These findings highlight the importance of maintaining treatment engagement.
Darius A. Rastegar, MD
Reference: Hickman M, Steer C, Tilling K, et al. The impact of buprenorphine and methadone on mortality: a primary care cohort study in the United Kingdom. Addiction. 2018;113(8):1461–1476.