Methadone is a prescription opioid medicine with a range of uses, including treating chronic non-cancer and cancer pain and, more commonly, opioid dependence. It is a common opioid agonist treatment (OAT). Those participating in a methadone treatment program are generally provided with a daily dose of the medicine in an oral solution or syrup, which is swallowed. Methadone is prescribed by a doctor as part of a treatment plan, with the dose and treatment duration based on the needs of the individual.

By providing a regular and stable opioid dose, methadone removes the need for additional opioids and helps to stabilise opioid-dependent individuals. Methadone can also promote changes in the routines and habits that may be associated with the use of heroin or other opioids. This can help a person achieve their treatment goals, which may be to become abstinent, or reduce their opioid use. Opioid dependence treatment using methadone can be long-term, lasting months or years as a form of maintenance therapy, or short-term for approximately five to 14 days to treat withdrawal...