Residual Effects of Short Half-life Non-benzodiazepine Hypnotics

Background Since their introduction at the beginning of the 1990s the short half-life nonbenzodiazepine hypnotics, zolpidem and zopiclone, rapidly were among the most frequently prescribed hypnotics. Surveys showed that around 1996 the most frequently prescribed hypnotic in the US was zolpidem, while zolpidem and zopiclone were among the five most frequently used hypnotics in Europe [1, 2]. Their popularity is probably due to a growing awareness among patients and prescribing physicians of the disadvantages of benzodiazepine hypnotics, in particular the development of tolerance and the potential for addiction. In addition, benzodiazepines changed normal sleep architecture by reducing the relative amounts of REM sleep and slow wave sleep (deep sleep), both considered essential sleep stages for mental and physical well being. Another disadvantage, in particular of the older benzodiazepine hypnotics, was their generally long half-life which resulted in significant residual effects. Although there were a number of short acting benzodiazepines, such as triazolam and midazolam, these drugs also had drawbacks such as rebound insomnia and problems with abrupt withdrawal. However, all these problems seemed to be less for short half-life hypnotics from other chemical classes, i.e., zolpidem and zopiclone. This probably explains their popularity.