RATIONALE: In 1998, the FDA
approved modafinil for treating excessive daytime sleepiness in
narcoleptics, and this has raised questions about the appropriateness of
this compound for enhancing alertness in sleep-deprived controls. This study
explored the efficacy of modafinil for maintaining the performance of
volunteers required to accomplish highly demanding tasks despite sleep loss.
OBJECTIVE: The principal
objective was to determine whether prophylactic doses of modafinil would
attenuate decrements in aviator performance and arousal throughout 2 days
and 1 night without sleep.
METHODS: Six pilots were exposed
to two 40-h periods of continuous wakefulness. In one, three 200-mg doses of
modafinil were given and in the other, matching placebos were administered.
Helicopter simulator flights, resting EEGs, and Profile of Mood States (POMS)
questionnaires were evaluated.
RESULTS: Modafinil attenuated
sleep deprivation effects on four of six flight maneuvers, reduced slow-wave
EEG activity, and lessened self-reported problems with mood and alertness in
comparison to placebo. The most noticeable benefits occurred between 0330
and 1130 hours, when the combined impact of sleep loss and the circadian
trough was most severe. The most frequently observed drug side effects were
vertigo, nausea, and dizziness. These could have been related to: 1) the
motion-based testing, 2) the use of a simulator rather than an actual
aircraft (i.e., "simulator sickness"), and/or 3) the
administration of more than 400 mg modafinil.
CONCLUSIONS: Modafinil is a
promising countermeasure for sleep loss in normals; however, additional
studies aimed at reducing side effects are needed before it should be used
in aviators.
