Residual sedating effects of ethanol.

To test for dose and duration effects of residual sedation, ethanol (0.0, 0.5, and 0.9 g/kg) was administered (at 0830, 1030, and 0730 hr, respectively) to 10 healthy, normal-sleeping men, aged 21-35 years. The Multiple Sleep Latency Test was conducted at 0930, 1130, 1330, 1530, 1730, 1930, and 2130 hr, and a divided attention performance assessment was done at 1400, 1600, 1800, and 2000 hr. Breath ethanol concentration for both doses was 0.04% at 1130 hr, 0.01% at 1330 hr, and 0 at 1530 hr. A significant reduction in sleep latency was observed from 0930 to 1530 hr, but not thereafter. Divided attention performance overall was significantly impaired on the 1400-hr test only. These data again showed residual sedation and suggest residual sedation is time limited and not affected in duration or intensity by dose.