ABSTRACT
The term ‘hypnotic’ is derived from the Greek hypnos, meaning ‘sleep’. A hypnotic drug produces drowsiness and promotes the onset and maintenance of sleep. The sleep induced by hypnotic drugs does not resemble the artificial state of suggestibility known as hypnosis. Sedation, sleep and general anaesthesia are generally regarded as being part of the same continuum of central nervous system depression. Thus, high doses of most hypnotic drugs can induce general anaesthesia. Several new hypnotics are currently in the late stages of clinical development, and include compounds which are structurally unrelated to benzodiazepines or barbiturates, but are agonists at the benzodiazepine receptor complex, such as zolpidem and zopiclone. Further benzodiazepines, such as midazolam and quazepam, are also being developed as hypnotics. The ideal hypnotic for the treatment of most insomnias would be a drug which produces a rapid onset of sleep, promotes the maintenance of sleep for a short period and then allows an immediate return to normal wake activity.
