Clinical issues in using buprenorphine in the treatment of opiate dependence

This paper looks at the current role of buprenorphine in the treatment of opiate dependence. It suggests that buprenorphine is a useful alternative to methadone and that in at least some cases it may be the preferred option. Buprenorphineis a partial agonist and a partial antagonist with a ceiling of opiate activity probably approximately equal to 30mg methadone. It achieves this at a dose of 10‐12mg, although there is considerable individual variation. Because of its ceiling effect it has a good safety profile compared to full agonists such as methadone although some overdose deaths, particularly in conjunction with benzodiazepine abuse, have been reported in France. Induction of buprenorphine may take slightly longer than for methadone and there is a higher dropout rate compared to methadone in the first 2 weeks. This is probably due to the antagonist action of buprenorphine causing more withdrawal symptoms in comparison to methadone. Also, the ceiling effect for buprenorphine means that some clients do not experience sufficient opiate activity to satisfy them. Buprenorphine has a long half‐life and dissociates slowly from opiate receptors. Most clients can be dosed second‐daily but some find this unacceptable due to mood swings and/or withdrawal symptomson the second day. For these clients daily dosing is required. Transferring from buprenorphine to methadone is straightforward and well tolerated by clients. Transferring from methadone to buprenorphine, however, is more difficult because of the partial antagonist action of buprenorphine. Clients experience withdrawal symptoms that can take up to 2 weeks to settle. Most clients find these symptoms unacceptable when transferring from doses of over 30mg of methadone. The optimum method for transferring from methadone to buprenorphine is still to be determined. Withdrawal from buprenorphine appears to be relatively easier than from methadone. This is presumably due to buprenorphine's partial agonist effect at mureceptors. It is expected that during 2000 buprenorphine will be approved for use in Australia for the treatment of opiate dependence. It may well becomea first‐line choice for opiate replacement in heroin dependence. It is also likely to be useful in assisting detoxification fromboth methadone and heroin.