Opiate maintenance with buprenorphine in ambulatory care: a 24-week follow-up study of new users

Background: Many studies suggest that buprenorphine, a long acting partial opioid agonist, may be comparable to methadone in efficacy, with fewer withdrawal symptoms and a lower risk of overdose. The aim of this study was to assess the patterns of buprenorphine prescription use in ambulatory care and retention rate under treatment during a 24-week follow-up period. Methods: This observational cohort study included buprenorphine users identified from the French Health System prescription database in an area of I million inhabitants and followed for 24 weeks. Results: We selected 282 users of buprenorphine defined as "new users" (74% male, mean age 32.4 +/- 6.2 years). Three groups were defined: 50% of "rational users" (141 subjects, no more than 2 prescribers), 24% of "occasional users" (67 subjects, less than 2 buprenorphine prescriptions) and 26% of "non-rational users" (74 subjects, 3 or more prescribers). The overall 24-week treatment retention rate was 37%. Misuse of butprenorphine or benzodiazepines was significantly more frequent in "non-rational" than "rational users". Conclusion: The retention rate with buprenorphine estimated in this observational study was very similar to that obtained in controlled trials. A majority of regular users of buprenorphine could be regarded as "rational users" in this area of France. (C) 2003 Elsevier Ireland Ltd. All rights reserved.