Diversion and injection of buprenorphine-naloxone film two years post-introduction in Australia

Introduction and Aims: We report 2 years of post-marketing surveillance of the diversion and injection of buprenorphine-naloxone (BNX) film following its introduction in 2011. Design and Methods: Interviews were conducted with people who inject drugs regularly (PWID) (2004-2013), opioid substitution therapy clients (2013, n = 492) and key experts (n = 44). Key outcomes were unsanctioned removal of supervised doses, diversion, injection and street price. Prevalence of past 6-month injection among PWID was adjusted for background availability of opioid substitution therapy medications using sales data. Results: Among out-of-treatment PWID, the levels of regular (weekly+) BNX film injection were comparable to methadone and BNX tablets, and lower than mono-buprenorphine, adjusting for background availability. Fewer BNX film clients [3%; 95% (CI) 1-5] regularly injected their medication than mono-buprenorphine clients (25%; 95% CI 11-39), but at levels equivalent to those among methadone (3%; 95% CI 1-6) and BNX tablet clients (2%; 95% CI 0-6). Key experts perceived BNX film needed less supervised dosing time as it dissolved rapidly and was harder to remove from the mouth than sublingual tablets; however, removal of supervised doses was higher among BNX film clients (15%; 95% CI: 10-20) than methadone clients (3%; 95% CI 1-6), and not significantly different from BNX tablet (11%; 95% CI 2-21) and mono-buprenorphine clients (31%; 95% CI 16-46). Discussion and Conclusions: Two years post-introduction, levels of BNX film diversion and injection remained comparable with those for methadone and BNX tablets, and lower than mono-buprenorphine. We found no evidence that BNX film has lower non-adherence and diversion than the tablet formulation.Briony Larance, Richard Mattick, Robert Ali, Nicholas Lintzeris, Rebecca Jenkinson, Nancy White, Ivana Kihas, Rosemary Cassidy, Louisa Degenhard