Substitution pharmacotherapies for opioid addiction: from methadone to LAAM and buprenorphine

The efficacy and cost-effectiveness of opioid substitution therapy for the treatment of opioid addiction has been well documented within the methadone maintenance model for over thirty years. However, methadone does not meet the specific treatment needs of all opioid-dependent persons who might benefit from substitution therapy; consequently, a significant proportion of heroin addicts remain untreated. The recent approval of l-alpha-acetylmethadol (LAAM) as a maintenance treatment agent represents the first opioid substitution alternative to methadone. LAAM is a fundamentally different medication than methadone, with unique pharmacological characteristics. Its use requires a different approach to the clinical management of opioid substitution therapy and a different medication delivery strategy. The availability of LAAM has potential important implications for patients, clinics, and the community at large. Full realization of its advantages could move opioid substitution therapy into mainstream medical care and draw into treatment a substantial number of new patients able to benefit from such treatment. Buprenorphine, the other new opioid substitution therapy under development, shares some common advantages with LAAM. Its high safety profile and low physical dependence liability make it uniquely suitable for a subset of addicts as well as an initial treatment of choice in the opioid substitution treatment armamentarium.