Switching from methadone to diamorphine: 2-year results of the German heroin-assisted treatment trial (2011)

BACKGROUND: Several international clinical studies have found diamorphine treatment for opioid-dependent patients to show significantly better effects compared with methadone maintenance treatment. AIMS: This analysis of the German trial of heroin-assisted treatment investigates the effects on patients' health and drug use after switching from 12-month methadone to 12-month diamorphine treatment under similar study conditions. METHODS: For a period of 24 months, the state of health was explored using the Opiate Treatment Index (OTI) health scale and the Symptom Checklist-90-R (SCL-90-R), while drug use and social situation by an extended version of the European Addiction Severity Index (EuropASI) every 6 months. Changes in these criteria were tested for significance by repeated measures analyses. Of the 434 patients, who started the 2nd year of study treatment, 90 were methadone-diamorphine switchers, and 344 received diamorphine for 2 years. RESULTS: In the 2nd year, the methadone-diamorphine switchers succeed in catching up with the diamorphine patients. After switching to diamorphine, significant improvements in health and use of street heroin and cocaine were achieved during 1 year of diamorphine treatment. CONCLUSIONS: The results of the course of methadone-diamorphine switchers are a methodologically independent contribution toward confirming the positive effects of diamorphine treatment for difficult-to-treat opioid-dependent patients. This study supports the hypothesis that changing from optimized methadone treatment under the conditions of the clinical trial to diamorphine treatment is associated with improvements in health and drug use behavior. The study's limitations are noted.