Long-term follow-up of orally administered diacetylmorphine substitution treatment.

BACKGROUND To assess the long-term course of the feasibility and safety of orally administered heroin [diacetylmorphine (DAM)] tablets in substitution treatment of severely addicted opioid users. DESIGN Open-label, prospective cohort study with 2 non-randomly assigned treatment arms: DAM tablets only (n = 128) or DAM tablets combined with injected DAM and/or other opioids (n = 237). The average duration of the observation period was 62 months. Study endpoints were the time to discharge from treatment and the number of serious adverse events. RESULTS Both patient groups had a higher than 70% retention rate after the first 48 months of treatment, with similar long-term retention rates (after 8 years both groups had retention over 50%). The physician-verified rate of serious adverse events was 0.01 events per application year among the exclusively oral substitution group (intention-to-treat analysis) during the last year of observation, and 0.005 events per application year in the other group. CONCLUSIONS Because of their feasibility and safety over years, DAM tablets may be a valuable long-term therapeutic alternative.