Methadone is an analgesic (painkiller) that was first created in Germany during World War II. Its actions on the body are similar to those of morphine, which, like heroin, is an opiate, or a drug made from the opium poppy. Methadone was approved by the U.S. Food and Drug Administration in August 1947 for use in the treatment of pain.

Methadone maintenance treatment for heroin addiction was developed in the mid-1960s by doctors Vincent Dole and Marie Nyswander. These doctors were responding to concerns about epidemics of heroin addiction, related health problems, deaths (especially among young people 15 to 35), and a high relapse rate among addicts. Methadone was able to ease the withdrawal symptoms of heroin addicts. Later, scientists determined that methadone could be used in long-term maintenance treatment. In other words, methadone use is maintained, or kept going continuously, rather stopped after a...