Usefulness of Temazepam and Zaleplon to Induce Afternoon Sleep

Military Medicine, Oct 2006 by Simons, Ries

Data Analysis

For all performance measures, δ scores were computed, based on the difference between results of the baseline session and the results of the six postsleep sessions. All repeatedly measured variables were tested in separate applications of repeated measures analysis of variance. Subjective ratings and actigraphy scores were compared by computing the Student's ß test for paired samples. For correlation analyses, Pearson's product moment correlation (r) was used under the null hypothesis that quantity and quality of sleep correlated with performance after the sleep.

Results

Eleven subjects completed the study. One subject was withdrawn due to a headache on arrival at the Institute on the first trial day. Mean subjective TST of sleep at home before the trial days was 7:58 hours (SD, 1:39). Mean quality score was 1.4 (SD, 1.8), indicating good sleep quality. No significant differences between treatment conditions were observed.

TST and Quality of the Afternoon Sleep

Mean scores on subjective sleep quality, subjective TST, objective TST, and fragmentation index are summarized in Table I. Compared with zaleplon and placebo, sleep with temazepam showed the best subjective quality (with zaleplon: p

Mean subjective TST was 20 to 66 minutes shorter than TST measured with actigraphy (Table I) and a moderate correlation between these variables was found (r = 0.60; p

Subjective Sleepiness (SSS)

Sleepiness scores increased significantly during the night shift (F^sub (6,231)^ = 14,93; p

Vigilance and Tracking (VigTrack)

In all treatment conditions, tracking (root mean square tracking error) and vigilance (percentage of omissions and number of false reactions) showed no significant changes during the night. There were no significant differences In performance during the night among temazepam, zaleplon, or placebo. No significant correlations were found between afternoon sleep variables and performance on the VigTrack.

Complex Information Processing (MAT)

Performance on tracking, resource management, system monitoring, and communication tasks showed no significant differences among temazepam, zaleplon, and placebo treatments. Reaction time on the system monitoring task was significantly longer after awakening compared to the baseline session (p

Maximal Isometric Muscle Power of the Underarm

As Figure 3 shows, maximal power of the underarm muscles decreased significantly during the night shift In all treatment conditions (F^sub (6,231)^ = 9.77; p

Discussion

Twenty milligrams of temazepam Induced the best afternoon sleep in terms of quality, TST, and fragmentation. This is in agreement with other studies in which temazepam was used to improve daytime sleep.7,21,22 Use of zaleplon showed no significant advantage over placebo. This is in line with results of Drake et al.,10 who found no increase of TST with 10 mg of zaleplon, but contrasted by the results of Whitmore et al.,11 who found a trend for a greater amount of daytime sleep with zaleplon. Sleep was significantly less fragmented with temazepam. This may be important, because fragmentation reduces the recuperative effects of sleep.23