Buprenorphine alone and in combination with naloxone in non-dependent humans

This study evaluated the effects of concurrent naloxone on the opioid agonist effects of buprenorphine, a mixed agonistantagonist marketed as an analgesic and under development as a treatment for drug abuse. In a residential laboratory seven non-physically-dependent opioid abuser volunteers received intramuscular buprenorphine (0.4 mg or 0.8 mg/70 kg) alone and in combination with naloxone (0.4 mg or 0.8 mg/70 kg) versus placebo. Buprenorphine produced dose-related opioid agonist effects on physiological and subjective measures. Concurrent naloxone attenuated the opioid agonist effects of buprenorphine. Thus, a combination product of buprenorphine and naloxone may have lower abuse liability than buprenorphine alone.