Effects of Alprazolam, Buspirone and Diazepam on Daytime Sedation and Performance

Abstract

In a double-blind, randomised, comparative study, 44 healthy volunteers received alprazolam 0.5mg, buspirone 5mg or diazepam 5mg orally 3 times each day for 7 consecutive days. Daytime sedation was evaluated on the first and seventh treatment days by the multiple sleep latency test by direct EEG measurements. Sleep was recorded the night preceding each test day to control for the influence of sleep on subsequent daytime sedation and performance. A vigilance visual-tracking/reaction-time test was used to examine daytime performance, while other symptoms of daytime sedation were subjectively assessed by questionnaires. During treatment day 1, alprazolam- and diazepam-treated subjects were significantly sleepier than subjects who received buspirone. Compared with buspirone, performance was significantly impaired for the alprazolam subjects but not for the diazepam group. On day 7 differences in daytime sleepiness and sleep latency were no longer significant. However, alprazolam- and diazepam-treated subjects exhibited significantly slowed reaction times on the performance test. These results suggest that buspirone may have potential as an anxiolytic agent for patients in whom daytime alertness must not be compromised.