DISRUPTED SLEEP-WAKE RHYTHM AND PERFORMANCE - ADVANTAGES OF MODAFINIL

The pharmacological approach to the management of vigilance during sus tained operations is a substantial aspect of circadian sleep-wake rhyt hm control. The use of psychotropic drugs has many advantages but also faces limits and constraints. The synthesis of new awakening compound s called eugregoric may completely change our approach to psychostimul ants. We review general pharmacological properties and current knowled ge for one of these molecules (modafinil) and report results of psycho motor tests performed during a 60-hr sleep deprivation experiment cond ucted on eight healthy military volunteers. The seven tests included a reaction time task, a mathematical processing task, a memory search t ask, a spatial processing task, an unstable tracking task, a grammatic al reasoning task, and a dual task combining unstable tracking with co ncurrent memory search. With the administration of modafinil in doses of 200 mg three times per day, the overall performance remained identi cal to that obtained during control trials without sleep deprivation. Performance after modafinil remained constant except for cyclic variat ions due to the influence of the endogenous circadian rhythm. After th e administration of a placebo, performance decreased more or less regu larly, depending on tasks, as a function of sleep deprivation and circ adian fluctuations. The efficacy of this substance and the observed ab sence of side effects make eugregoric molecules in general, and modafi nil in particular, valuable pharmacological tools and promising medici nes for military and emergency health care applications during extende d duty cycles and for therapeutic purposes.