COMPARISON OF THE EFFECTS OF ZOLPIDEM-INDUCED PROPHYLACTIC NAPS TO PLACEBO NAPS AND FORCED REST PERIODS IN PROLONGED WORK SCHEDULES

The efficacy of zolpidem-induced prophylactic naps was compared to pla cebo naps and forced-rest periods for sustaining alertness. Eighteen s ubjects were exposed to three separate 38-hour periods of continuous w akefulness, each separated by 10 hours of recovery sleep. Three condit ions were used: a 2-hour evening nap (at 2100 hours) induced with 10 m g zolpidem tartrate; a 2-hour nap (at 2100 hours) with placebo; and a 2-hour rest break with no sleep. Following the naps or rest period, su bjects remained awake for 23 additional hours. A VAS was administered at 1-hour intervals, RTSWs and POMS were administered at 2-hour interv als, and a cognitive task was completed at 4-hour intervals. Results i ndicated the effectiveness of prophylactic naps for sustaining mood, a lertness, and performance throughout the final 23 hours of a 39-hour p eriod of sustained operations. Both napping conditions attenuated the decrements normally associated with total sleep deprivation, but the z olpidem nap was the most effective because subjects obtained the most sleep after zolpidem administration. Postnap grogginess persisted for about 2 hours after either the zolpidem or placebo nap, a fact which, despite the overall benefits from prophylactic naps, could compromise performance under operational conditions if insufficient time for awak ening is planned.