Effect of the 1,5-benzodiazepines, clobazam and triflubazam, on sleep in man.

1 The effect of the 1,5-benzodiazepines, clobazam (10 and 20 mg) and triflubazam (20 and 40 mg), on sleep was studied in six healthy males using electroencephalography for sleep measures and analogue scales for subjective assessments of well being and sleep quality. The effect of clobazam was limited to the night of ingestion. There was some evidence from subjective assessments that the effect of triflubazam may have persisted beyond the night of ingestion. 2 No effect of clobazam or triflubazam was observed on total sleep time, stage shifts in the first 6 h or latency to the first rapid eye movement period of sleep. With clobazam sleep onset latency was shortened (P less than 0.05), but this effect was not seen with triflubazam. The latency to stage 3 was shortened by both drugs. There was evidence of reduced duration of awake (stage 0) activity and drowsy (stage 1) sleep with both drugs. 3 The percentage stage 1 sleep was reduced by clobazam (10 and 20 mg) and by triflubazam (20 mg) (P less than 0.05), though the effect was not significant with triflubazam (40 mg). Clobazam (20 mg) increased the percentage stage 2 sleep (P less than 0.05), but reduced the percentage stage 3 (P less than 0.01) and stages 3 + 4 (P less than 0.05) sleep. There were no other effects on percentage of total sleep time occupied by various sleep stages or in duration (min) of sleep stages, except that the duration (min) of sleep stages, except that the duration (min) of stage 2 sleep in the second 2 h interval of sleep was increased with clobazam (20 mg) (P less than 0.01). 4 Subjects reported impaired sleep with triflubazam (40 mg) (P less than 0.05), and a sense of less wakefulness the morning after ingestion of clobazam (10 and 20 mg) (P less than 0.01) and triflubazam (40 mg) (P less than 0.05).