EFFECTS OF BUPRENORPHINE ON BEHAVIOR MAINTAINED BY HEROIN AND ALFENTANIL IN RHESUS-MONKEYS

The mechanism by which buprenorphine reduces opioid self-administratio n in humans and animals is generally thought to be through its opioid agonist effects. Buprenorphine, given acutely i.v. to three rhesus mon keys 30 min prior to a session in which a range of doses of either alf entanil or heroin was available, produced dose-related decreases in th e potency of both opioid agonists. The effects of buprenorphine were g enerally surmounted by increasing the dose/injection of alfentanil or heroin available for self-administration, indicating that buprenorphin e was acting as an opioid antagonist in this situation. These data sug gest that at least part of the effectiveness of buprenorphine in reduc ing opioid administration by human opioid users may be via its opioid antagonist properties.