Pharmacotherapy of transient insomnia related to night work.

Shiftworkers working on the night shift transpose their sleeping hours to the time of day which is inconvenient for sleep because of the endogenous circadian rhythm sleep wakefulness, the circadian rhythms of other body functions and the environmental schedule. As a result of this, a certain number of workers suffer from insomnia. This study aimed at examining the effects of two hypnotic agents with different elimination times on sleep disturbances which follow night shift work. Three groups of shiftworkers took zopiclone, nitrazepam and placebo capsules during a week of work on the night shift repeating it three times so that each week of capsule taking was separated from the next by a three-week break. In the two groups on hypnotics total length and efficacy of main sleep improved as did the efficacy of all day sleeps at the very beginning of the week, and these sleep characteristics persisted throughout the week. In contrast, in the group which took a placebo sleep was shorter and loss efficacious at the beginning but improved towards the end of the week. There was no negative effect of hypnotics on the shiftworker's mood after waking up. To an extent, the hypnotics proved to be useful for periodical pharmacological improvement of the length and efficacy of day sleep after night work in the slowly rotating shift system.