Daytime sleepiness as a criterion in hypnotic medication trials: comparison of triazolam and flurazepam.

Sleep laboratory hypnotic medication trials typically determine efficacy by examining changes in polysomnographically recorded sleep. We introduce the use of daytime sleepiness, as assessed by the Multiple Sleep Latency Test (MSLT), as a criterion for daytime functioning in such trials. Two benzodiazepine hypnotics, triazolam (0.5 mg) and flurazepam (30 mg), with short and long half-lives respectively, were compared in a multicentered, double-blind crossover study. Results indicated these medications had virtually indistinguishable nocturnal effects, but differed dramatically during the day. Flurazepam decreased sleep latency on the MSLT, whereas triazolam did not. These results could indicate that daytime sleepiness is a concomitant effect of flurazepam.