PERFORMANCE, ABILITY TO STAY AWAKE, AND TENDENCY TO FALL ASLEEP DURING THE NIGHT AFTER A DIURNAL SLEEP WITH TEMAZEPAM OR PLACEBO

Sleep loss and increased sleepiness on the job are among the most prev alent problems encountered by people involved in night shift work, esp ecially in cases of abrupt shift of the wake-sleep cycle. In such cond itions, detrimental effects on performance are well documented. In the se situations, to avoid decrements of performance at night, one possib ility is to use hypnotics for improving the quality and quantity of da ytime sleep. In this study, we evaluated the effects of 20 mg of temaz epam on daytime sleep, the subsequent levels of nocturnal alertness/sl eepiness, and performance in a laboratory simulation of acute night sh ift. For evaluating alertness, sleepiness, and performance we used, re spectively, the maintenance of wakefulness test (MWT), the multiple sl eep latency test (MSLT), and two pencil and paper tests: digit symbol substitution rest (DSST) and deux barrages test (DBT). All tests were administered four times 2-hour intervals during the nighttime after da ytime sleep. Results showed that the ability to maintain wakefulness ( MWT) and to perform some visuo-attentive tasks were substantially main tained during the night. On the other hand, sleep tendency (MSLT) line arly increased during the night. Temazepam resulted in being an effect ive diurnal hypnotic, increasing total sleep time with no residual det rimental effects on sleepiness and performance and with an increase in the ability to stay awake.