Studies on sleep and performance with a triazolo-1, 4-thienodiazepine (brotizolam)

1 Brotizolam, a triazolo-1,4-thienodiazepine, was studied in healthy young adults. Electroencephalographic sleep variables and subjective effects, and performance on a visuo-motor coordination task were measured. 2 In the sleep studies six males each ingested 0.2, 0.4 and 0.6 mg brotizolam overnight. All doses increased total sleep time, improved the sleep efficiency index, and reduced drowsy sleep and number of awakenings. Brotizolam 0.4 and 0.6 mg also reduced awake activity and increased stage 2 sleep. There was some evidence of a delay to the first REM period, but only 0.6 mg reduced the total duration of REM sleep. There were no changes in slow wave sleep. 3. In the performance studies six females each ingested 0.4 mg in the morning and 0.2, 0.4 and 0.6 mg brotizolam at night. After morning ingestion of 0.4 mg there was impaired performance from 0.5 to 5.5 h. There were no residual effects after 0.2 mg brotizolam, but with 0.4 mg there was a residual effect at 9.5 h, and 0.6 mg led to impairments up to 15.0 h after ingestion. 4 Brotizolam is a short-acting hypnotic. In doses around 0.2 mg it has useful hypnotic activity free of adverse effects on sleep and residual effects on performance. With 0.4 mg the hypnotic effect is enhanced with only minimal residual effects.