Methadone is an opioid medication. An opioid is sometimes called a narcotic. Methadone also reduces withdrawal symptoms in people addicted to heroin or other narcotic drugs without causing the "high" associated with the drug addiction. Methadone is used as a pain reliever and as part of drug addiction detoxification and maintenance programs. Methadone is available only from a certified pharmacy. Methadone may also be used for purposes not listed in this medication guide.