Sleep and Alertness Management IV: Effects of Alertness Enhancers Caffeine and Modafinil on Performance in Marmosets

Abstract : Flumazenil might be effective to maintain normal performance in case of an alertness demanding situation directly after taking a hypnotic. However, in case personnel have to be alert during a time of the day that the circadian rhythm is programmed for sleep, the use of wake promoting drugs `night be more efficient. The alertness enhancer caffeine counteracted the sleep deprivation induced decline on the performance and activity. Modafinil even improved the activity. Chronic use of caffeine or modafinil did not negatively affect the performance and the activity during daytime and resulted in comparable effects as after a single use of these compounds. This means that caffeine and modafinil are both effective in reducing the sleep deprivation induced declines in performance. Moreover, the stimulants remain effective when used in combination with a hypnotic and even after chronic use no worsening of day time performance was observed. Modafinil reach its maximum effect 2-4 hours after oral administration indicating that it can only be used in situation in which the operation is planned by forehand. Caffeine, a fast and short acting compound, should be useful for short scenarios. In case long term improved alertness is needed a slow release administration will be needed.