Editor's note

Misuse and dependence upon benzodiazepines, despite much greater awareness of the dangers of these drugs, still appear to be growing problems. Misuse occurs because of dependency upon these drugs that have been prescribed for extended periods with some increasing tolerance on the part of the patient. Misuse also occurs by people who purchase or obtain these drugs by means other than prescription. The growing emphasis on insomnia and the increasing competition among various drug companies to capture the prescription sleeping pill market appears to exacerbate this problem. At the moment, a gradual tapering of the prescribed or illegally used drug, especially by substituting a longer-acting drug for a shorter-acting drug, appears to have the most supporting evidence. Little research has been done on hypnotics compared with the benzodiazepines, and this is a bit of a puzzle.

Introduction

Sedative hypnotic drugs are central nervous system depressants traditionally used to reduce anxiety and induce sleep. The sedatives under consideration in this chapter are benzodiazepines, the Z-drugs (zopiclone, zolpidem and zaleplon) and barbiturates. After their introduction in 1903, barbiturates were supplanted by the benzodiazepines which were introduced in the early 1960s. This was primarily due to concerns about the obvious toxicity of barbiturates, particularly in overdose, and knowledge of their propensity for dependence. After reaching a peak in the early 1980s, prescriptions for benzodiazepines in the UK have shown a substantial reduction; however, while annual prescriptions for benzodiazepines in England fell from 10 million to around 6 million between 1993–2003, those for the Z-drugs rose from 0.3 million to over 4 million over the same time period, mainly in older people (DoH, 2003), and this is a worldwide phenomenon.