This class of central nervous system depressant drugs facilitates, induces or maintains sleep. Other classes, such as sedatives, sedative-hypnotics, and anxiolytics, which are similar in effect and are often used interchangeably, overlap. Drugs from the chemical classes benzodiazepines and barbiturates are sometimes included. Some of these drugs may also be used to induce or as an adjunct to general anesthesia and narcosynthesis.
