The concomitant effects of mild sleep loss and an anticholinergic drug

Thirty-seven young men were tested in drug-along, sleep-loss-alone, and sleep-loss-drug groups to determine the separate and combined effects of mild sleep loss and scopolamine hydrobromide. Scopolamine was administered intravenously in either a sedative dose (5 μg/kg) or a low deliriant dose (10 μg/kg); sleep deprivation was for either one or two nights. Attention, accuracy, motor skill and behavior were measured and rated. An analysis of the results revealed that either dose of scopolamine given after loss of sleep caused significantly more intense and prolonged psychotomimetic effects than were noted in the drug-alone condition. Unlike the psychotomimetic effects, the results on sedation were not uniform. Those men who recieved 5 μg/kg of scopolamine following sleep deprivation showed increased somnolence, whereas the reverse was true for the 10 μg/kg scopolamine-sleep-loss subjects.