Buprenorphine: a controlled clinical trial in the treatment of opioid dependence

Clinical trials carried out to compare methadone and buprenorphine in the treatment of opioid dependence have generally employed an alcoholic solution of buprenorphine, which has a bioavailability superior to that of the tablets. Since the product available for large scale use is in tablet form, one intended to verify the efficacy of this formulation. In a multicentre randomised controlled double blind study, 72 opioid dependent patients were assigned to treatment with buprenorphine (8 mg/day) or methadone (60 mg/day) for a period of 6 months. The two compounds did not show any significant difference with regard to urinalyses: the average percentage of analyses proving negative was 60.4% for patients assigned to buprenorphine, and 65.5% for those assigned to methadone. With regard to retention, a non-significant trend in favour of methadone was observed. Patients completing the trial improved significantly in terms of psychosocial adjustment and global functioning, as ascertained by the DSM-IV-GAF and symptom checklist-90 (SCL-90) scales, and this was independent of the treatment group. Finally, in the case of buprenorphine, patients who dropped out differed significantly from those who stayed, in terms of a higher level of psychopathological symptoms, and a lower level of psychosocial functioning. The results of the study further support the utility of buprenorphine for the treatment of opioid dependence.