Efficacy of Dexedrine (R) for maintaining aviator performance during 64 hours of sustained wakefulness: A simulator study

Introduction: The efficacy of Dexedrine(R) for sustaining aviator performan ce despite 64 h of extended wakefulness was investigated. This study was co nducted to extend the findings of earlier research that had proven the effi cacy of Dexedrine during shorter periods (i.e., 40 h) of sleep deprivation. Methods: Dexedrine (10 mg) or placebo was given at midnight, 0400, and 080 0 hours on two deprivation days in each of two 64-h cycles of continuous wa kefulness. Test sessions consisting of simulator flights, electroencephalog raphic evaluations, mood questionnaires, and cognitive tasks were conducted at 0100, 0500, 0900, 1300, and 1700 hours on both deprivation days. Two ni ghts of recovery sleep separated the first and second 64-h sleep-deprivatio n cycles. Results: Simulator flight performance was maintained by Dexedrine throughout sleep deprivation. The most benefit occurred at 0500 and 0900 h ours (around the circadian trough) on the first deprivation day, but contin ued throughout 1700 hours (after 58 h awake) on the second day. Dexedrine s uppressed slow-wave EEG activity which occurred under placebo after 23 h aw ake and continued to exert this effect throughout 55 h (and sometimes 59 h) of deprivation. The drug sustained self-perceptions of vigor while reducin g fatigue and confusion. Recovery sleep was slightly less restful under Dex edrine. Conclusions: Dexedrine sustained aviator performance and alertness during periods of extended wakefulness, but its use should be well controll ed. Although effective, Dexedrine is no replacement for adequate crew rest management or restful sleep.