Alertness-enhancing drugs as a countermeasure to fatigue in irregular work hours.

Irregular work/rest patterns frequently cause disturbed sleep and excessive sleepiness and accidents. This review is focused on four pharmacological countermeasures-the "new" drugs modafinil and pemoline, the traditional caffeine, and, as a reference, amphetamine. It is concluded that there is still too little data available to decide whether systematic use of alertness-enhancing drugs is feasible in occupational settings. D-Amphetamine is ruled out because of its abuse potential and mood effects. Modafinil and pemoline have not been tested in field situations, whereas caffeine certainly is used to improve alertness during work, but the use is spontaneous/ad hoc, and there is still a lack of data on its systematic application. Particularly, the optimal amount and pattern of administration need elucidation.