Effects on night-time motor activity and performance in the morning after midazolam intake during the night.

The hypnotic action and residual effects of a single night-time dose of midazolam (Ro 21-3981, Dormicum, 7.5 mg; CAS 59467-70-8) were investigated in young, healthy adults. The subjects went to bed at the habitual time and were awakened 3 h later for drug or placebo intake. Then they were allowed to continue their sleep. Motor activity was continuously recorded by a wrist-worn activity monitor. In comparison to placebo, prolonged night-time immobility periods were more frequent after midazolam. Sleep tended to be perceived as more quiet and as less interrupted by awakenings. 15 min after awakening in the morning, the subjects felt more relaxed after midazolam than after placebo. Performance assessed 2 h after awakening by a psychomotor test showed no decrement. The results show that a 7.5-mg dose of midazolam taken in the first half of the night has a significant hypnotic action without impairing psychomotor performance in the morning.