Buprenorphine is a partial agonist at the μ-opioid receptor that has been proposed as an alternative to traditional full agonist maintenance therapy for the treatment of opioid addiction. We report on a clinical trial in which the relative safety and efficacy of long-term fixeddose buprenorphine maintenance was examined in comparison to low- and high-dose methadone maintenance.
Two hundred twenty-five treatment-seeking opioid addicts (46 women, 179 men) were randomly assigned to receive, in a double-blind manner, either 8 mg/d of buprenorphine, 30 mg/d of methadone, or 80 mg/d of methadone maintenance over a 1-year period. Objective and subjective measures of efficacy (urine toxicology, retention, craving, and withdrawal symptoms) were examined at the study midpoint and at termination, and safety data were tabulated over the entire 52-week study period.
Patients assigned to high-dose methadone maintenance performed significantly better on measures of retention, opioid use, and opioid craving than either the low-dose methadone or the buprenorphine group at both 26-week and 52-week time points. Performance on these measures was virtually identical between the latter two groups. No serious adverse health effects attributable to buprenorphine were noted.
Buprenorphine maintenance at 8 mg/d appears to be less than optimally efficacious under the conditions of the present study. Continued research is needed to reconcile these findings with the more positive results reported by other investigative groups. There are no apparent health risks associated with long-term buprenorphine maintenance at this dosage.