ICD-11 Criteria for Disorders Due to Use of Opioids (6C43) Disorders due to use of opioids are characterised by the pattern and consequences of opioid use. Opioids is a generic term that encompasses the constituents or derivatives of the opium poppy Papaver somniferum as well as a range of synthetic and semisynthetic compounds, some related to morphine and others chemically distinct but all having their primary actions on the µ opioid receptor. Examples of opioids include morphine, diacetylmorphine (heroin), fentanyl, pethidine, oxycodone, hydromorphone, methadone, buprenorphine, codeine and d-propoxyphene. The opioids all have analgesic properties of different potencies and are primarily central nervous system depressants. They suppress respiration as well as other vital functions and are a common cause of overdose and related deaths. Certain opioids are used or administered parenterally, including heroin, a common and potent opioid that is primarily used non-medically. Therapeutic