Effects of temazepam 7.5 mg and temazepam 15 mg on sleep maintenance and sleep architecture in a model of transient insomnia

OBJECTIVE: To compare the effects of temazepam 7.5 mg and temazepam 15 mg on sleep maintenance during the last third of the night (last 160 min) and on sleep architecture throughout the night. RESEARCH DESIGN AND METHODS: This was a retrospective analysis of a previously reported double-blind, randomized, uncontrolled, parallel-group, multicenter study. Healthy subjects with previous but no current complaints of transient insomnia were enrolled. Transient insomnia was induced in the sleep laboratory by means of the 'first night' effect and by implementing a 2-h phase advance. The effects of both doses of temazepam on polysomnographic measures of sleep were evaluated for 1 night. The primary, prospectively-defined analysis of this study showed that 7.5-mg and 15-mg doses of temazepam had equivalent effects on latency to persistent sleep, total sleep time, and the number of sleep interruptions recorded over an 8-h period. Both doses were well tolerated. The post hoc analysis reported here compared these 2 doses for their effects on sleep maintenance and architecture. Sleep efficiency during the last third of the night was designated as the primary endpoint. The methodology for this analysis was fully defined and documented prior to re-analysis of the database for these parameters. RESULTS: Sixty-five subjects received temazepam 7.5 mg and 66 received temazepam 15 mg. No statistically significant differences between doses were detected for sleep efficiency or number of sleep interruptions during the last third of the night. Sleep architecture (measured over 8 h) did not differ significantly between groups. CONCLUSIONS: The 7.5-mg and 15-mg doses of temazepam were equally effective for maintaining sleep during the last third of the night. Continuity of sleep throughout the night, as reflected by sleep architecture, was also similar regardless of dose. In keeping with current practice guidelines, initiation of treatment with temazepam for transient insomnia should begin with the 7.5 mg dose.