6. Is the use of medications like methadone simply replacing one drug addiction with another?
No. As used in maintenance drug addiction treatment, methadone and LAAM are not heroin substitutes. They are safe and effective medications for opiate addiction that are administered by mouth in regular, fixed doses. Their pharmacological effects are markedly different from those of heroin.
As used in maintenance treatment, methadone and LAAM are not heroin substitutes.
Injected, snorted, or smoked heroin causes an almost immediate "rush" or brief period of euphoria that wears off very quickly, terminating in a "crash." The individual then experiences an intense craving to use more heroin to stop the crash and reinstate the euphoria. The cycle of euphoria, crash, and craving - repeated several times a day - leads to a cycle of addiction and behavioral disruption. These characteristics of heroin use result from the drug's rapid onset of action and its short duration of action in the brain. An individual who uses heroin multiple times per day subjects his or her brain and body to marked, rapid fluctuations as the opiate effects come and go. These fluctuations can disrupt a number of important bodily functions. Because heroin is illegal, addicted persons often become part of a volatile drug-using street culture characterized by hustling and crimes for profit.
Methadone and LAAM have far more gradual onsets of action than heroin, and as a result, patients stabilized on these addiction medications do not experience any rush. In addition, both medications wear off much more slowly than heroin, so there is no sudden crash, and the brain and body are not exposed to the marked fluctuations seen with heroin use. Maintenance treatment with methadone or LAAM markedly reduces the desire for heroin. If an individual maintained on adequate, regular doses of methadone (once a day) or LAAM (several times per week) tries to take heroin, the euphoric effects of heroin will be significantly blocked. According to research, patients undergoing maintenance treatment do not suffer the medical abnormalities and behavioral destabilization that rapid fluctuations in drug levels cause in heroin addicts.
Source: National Institute of Drug Abuse, "Principles of Drug Addiction Treatment: A Research Based Guide