[Circadian variations of the effects of ethanol and of blood ethanol values in the healthy adult man. Chronopharmacological study].

Six healthy young men (22 to 26 years) who had fasted for 12 hours volunteered for this study (subject synchronization: diurnal activity from 07(00) to midnight and nocturnal rest). A set dose of ethanol (0.67 g/kg body weight) was ingested at the fixed (and random) hours of 07(00), 11(00), 19(00) and 23(00), with a week between tests. A set of physiological variables: psychological tests (selft-rating of mood, of physical vigor and of ebriety, tempo, random number addition test); physical variables (heart rate, systolic and diastolic blood pressure, peak expiratory flow, oral temperature and grip strength); blood variables (plasma ethanol, cortisol, lactic acid, pyruvic acid, glucose and erythrocyte K+) and urinary variables (volume, epinephrine, nor-epinephrine and 5-HIAA) were documented at least at 4 hourly intervals and set times. The cosinor method was used for chronobiological statistical analyses. The parameters characterizing the ethanol pharmacokinetics (chronopharmacokinetics) demonstrated a circadian rhythm (p less than 0.05): e. g. the peak height of ethanolemia is greater when ethanol is ingested at 07(00) than at other times. Also a circadian rhythm in biosystems susceptibility can be demonstrated (p less than 0.05) (chronesthesy) with a peak time not necessarily corresponding either to that of ethanolemia or to that of other variables. The overall circadian changes in ethanol effects (chronergy) can be viewed as a combination of both ethanol chronesthesy and chronokinetics.