The diversion and injection of a buprenorphine-naloxone soluble film formulation

Abstract

Background: We compared the diversion and injection of a new formulation of buprenorphine, a buprenorphine-naloxone film product (BNX film), with buprenorphine-naloxone tablets (BNX tablets), mono-buprenorphine (BPN) and methadone (MET) in Australia.

Methods: Surveys were conducted with people who inject drugs regularly (PWID) (2004-2012) and opioid substitution treatment (OST) clients (2012, N=543). Key outcome measures: the unsanctioned removal of supervised doses, diversion, injection, motivations, drug liking and street price. Levels of injection among PWID were adjusted for background availability of medication using sales data. Doses not taken as directed by OST clients were adjusted by total number of daily doses dispensed.

Results: Among out-of-treatment PWID, levels of injection for BNX film were comparable to those for MET and BNX tablet formulations, adjusting for background availability; BPN injecting levels were higher. Among OST clients, recent injecting of one's medication was similar among clients in all OST types; weekly or more frequent injection of prescribed doses was reported by fewer BNX film clients (3%; 95% CI: 1-6) than BPN clients (11%; 95% CI: 3-17), but at levels similar to those observed among MET and BNX tablet clients. The proportion of BNX film doses injected was lower than that for BPN and BNX tablets, and equivalent to that for MET. The majority of BNX film doses injected by OST clients were unsupervised doses, although some injection of supervised doses of BNX film did occur. The median price of all buprenorphine forms on the illicit market was the same.

Conclusions: Non-adherence and diversion of the BNX film formulation was similar to MET and BNX tablet formulations; BPN had higher levels of all indicators of non-adherence and diversion.

Keywords: Abuse liability; Compliance; Methadone; Opioid substitution therapy; Post-marketing surveillance.