Effects of flurazepam and zolpidem on the perception of sleep in insomniacs.

We have shown previously that the benzodiazepine hypnotic triazolam alters the perception of being awake or asleep in insomniacs, making it more likely that they will report having been asleep when awakened by an electronic tone at various times of the night. In the present study, we examined the question as to whether this is also true for other benzodiazepines as well as for nonbenzodiazepine hypnotics. Ten insomniacs were given placebo, flurazepam 30 mg and zolpidem 10 mg and were awakened at five times during subsequent sleep in a random-sequence repeated-measures study. Across all five awakenings following placebo, insomniacs reported being asleep with a frequency of 30.9%. This rose to 40.4% (ns) and 54.7% (p < 0.03) on flurazepam and zolpidem, respectively. Subjects were also more likely to report having been dreaming during the awakening 5 minutes after "lights out" after receiving zolpidem. A number of polygraphic measures of sleep, including sleep latency, total sleep and sleep efficiency, improved significantly on both drugs, and there was similar improvement in some global measures of quality of sleep. Neither drug altered the subjective sense of duration of time. These findings suggest that drug-induced alterations in the perception of being awake or asleep are not unique to benzodiazepines, but occur with the nonbenzodiazepine zolpidem as well.