Antagonism by alpha methyltyrosine of the ethanol‐induced stimulation and euphoria in man

Abstract

The effect of α‐methyl‐p‐tyrosine (α‐MT) pretreatment on ethanol‐induced behavioral effects in man was studied using a crossover, double‐blind design. Two dose‐regimens of α‐MT were used (4 × 1 gm and 4 × 0.5 gm, respectively, given 26,18,10, and 2 hours before the ethanol intake) in two separate experiments in 10 male subiects. The ethanol was administered orally as hard liquor (43%, vol/vol) in a dose of 50 ml every tenth minute for 40 minutes. The degree of general intoxication and certain other behavioral variables were rated by 3 nonintoxicated observers and by the subiects themselves, using a graded scale. Some obiective performance tests were also used. Pretreatment with α‐MT caused a reduction of the ethanol‐induced stimulation and euphoria as indicated by a significant decrease in the observers' ratings of alertness, talkativeness, elation, and happiness. Fatigue was significantly increased. These observations were supported by the subiects' own general annotations and, in part, by their own ratings. α‐MT‐pretreatment per se caused marked fatigue with mild dysphoria and a feeling of discomfort. It is suggested that central catecholamines may be involved in ethanol‐induced stimulation and euphoria in man.