BUPRENORPHINE VS METHADONE-MAINTENANCE TREATMENT FOR CONCURRENT OPIOID DEPENDENCE AND COCAINE ABUSE

Background: Buprenorphine, a partial p-agonist and kappa-antagonist, h as been proposed as an alternative to methadone for maintenance treatm ent of opioid dependence, especially for patients with concurrent coca ine dependence or abuse. This study evaluated whether higher maintenan ce doses of buprenorphine and methadone are superior to lower doses fo r reducing illicit opioid use and whether buprenorphine is superior to methadone for reducing cocaine use. Methods: A total of 116 subjects were randomly assigned to 1 of 4 maintenance treatment groups involvin g higher or lower daily doses of sublingual buprenorphine (12 or 4 mg) or methadone (65 or 20 mg) in a double-blind, 24-week clinical trial. Outcome measures included retention in treatment and illicit opioid a nd-cocaine use as determined by urine toxicology testing and self-repo rt. Results: There were significant effects of maintenance treatment o n rates of illicit opioid use, but no significant differences in treat ment retention or the rates of cocaine use. The rates of opioid-positi ve toxicology tests were lowest for treatment with 65 mg of methadone (45%), followed by 12 mg of buprenorphine (58%), 20 mg of methadone (7 2%), and 4 mg of buprenorphine (77%), with significant contrasts found between 65 mg of methadone and both lower-dose treatments and between 12 mg of buprenorphine and both lower-dose treatments. Conclusions: T he results support the superiority of higher daily buprenorphine and m ethadone maintenance doses vs lower doses for reducing illicit opioid use, but the results do not support the superiority of buprenorphine c ompared with methadone for reducing cocaine use.