Temporal relations between blood alcohol concentration and alcohol effect: an experiment with human subjects.

Each of 40 fasting human subjects (20 men and 20 women) consumed 1 g ethanol (absolute) per kilogram body weight as a 20% solution by volume in orange juice. The time to peak BAC was found to be 24.0 min later than the time to peak alcohol effect as measured by magnitude estimation. This difference is both large and statistically reliable. These data are compared with those in the literature which usually show these events to be synchronous. Discussion includes reasons for this empirical discrepancy, implications of the theory of acute tolerance, and plans for future research. Examination of group data shows the same general trends obtained in the analysis of individual data: alcohol-effect scores reach peak earlier than BAC for the group as a whole (n = 40), or for men alone, or for women alone. Moreover, alcohol-effect scores decline more rapidly in later trials than BAC scores, as has been reported earlier.