agonist methadone. Prolonged oral treatment with this medication diminishes and often eliminates opiate use, reduces transmission of many infections, including HIV and hepatitis B and C, and reduces criminal activity. Evidence is now accumulating that suggests the effectiveness in such patients of LAAM and buprenorphine. For more than 30 years, the daily oral administration of methadone has been used to treat tens of thousands of individuals dependent upon opiates in the United States and abroad. The effectiveness of MMT is dependent on many factors, including adequate dosage, duration plus continuity of treatment, and accompanying psychosocial services. A dose of 60 mg given once daily may achieve the desired treatment goal: abstinence from opiates. But higher doses are often required by many patients. Continuity of treatment is crucial—patients who are treated for less than 3 months generally show little or no improvement, and most, if not all, patients require continuous treatment over a period of years, and perhaps for life. Therefore, the program has come to be termed methadone "maintenance" treatment (MMT). Patient attributes that have sometimes been linked to better outcomes include older age, later age of dependence onset, lesser abuse of other substances including cocaine and alcohol, and lesser criminal activity. Recently, it has been reported that high motivation for change has been associated with positive outcomes.
The effectiveness of MMT is often dependent on the involvement of a knowledgeable and empathetic staff and the availability of psychotherapy and other counseling services. The latter are especially important since individuals with opiate dependence are often afflicted with comorbid mental and personality disorders.
Because methadone-treated patients generally are exposed to much less or no intravenous opiates, they are much less likely to transmit and contract HIV and hepatitis. This is especially important since recent data have shown that up to 75 percent of new instances of HIV infection are attributable to intravenous drug use. Since for many patients a major source of financing the opiate habit is criminal behavior, MMT generally leads to much less crime.
Although methadone is the primary opioid agonist used, other full and partial opioid agonists have been developed for treatment of opiate dependence. An analog of methadone, levo-alpha acetyl-methadol (LAAM) has a longer half-life than methadone and so can be administered less frequently. A single dose of LAAM can prevent withdrawal symptoms and drug craving for 2 to 4 days. Buprenorphine, a recently developed partial opiate agonist, has the advantage over methadone that its discontinuation leads to much less severe withdrawal symptoms. The use of these medications is at an early stage, and it may be some time before their usefulness has been adequately evaluated.