[The medicine and drug-abusing patient].

: Opioids are frequently used in chronic cancer and non-cancer pain conditions. Addiction may develop during long-term opioid treatment and illegally as intravenous "street" addiction. Benzodiazepines are frequently used for legal indications. However, due to widespread misuse efforts are being made to limit consumption. Finally, an increasing number of illegal drugs--sedatives as well as psychoactive drugs--have recently been introduced to the illegal market. This review gives guidelines for the perioperative management of patients using and misusing these drugs.