The clinical efficacy and abuse potential of combination buprenorphine-naloxone in the treatment of opioid dependence.

BACKGROUND: Opioid dependence is a chronic relapsing condition for which long-term opioid substitution treatment (OST) is effective. However, safety and community acceptance of OST is compromised by diversion of prescribed medication. The development of a formulation combining buprenorphine and naloxone is designed to reduce the likelihood of intravenous misuse, and the therefore the value of the medication if diverted to the black market.

OBJECTIVE: To evaluate the evidence for 4:1 buprenorphine-naloxone as an efficacious OST, and as a deterrent to diversion and intravenous misuse.

METHODS: The literature on buprenorphine-naloxone in a 4:1 ratio is reviewed.

RESULTS/CONCLUSION: The addition of naloxone does not appear to affect the efficacy of buprenorphine as a maintenance drug. While offering some deterrence of injection through precipitated withdrawal, there are many circumstances where injecting of buprenorphine-naloxone is reinforcing rather than aversive. The combination will reduce, but not eliminate, intravenous misuse; clinicians therefore need to monitor patients in OST, and be selective in providing patients with medication to be taken without observation.