Norepinephrine metabolism and clinical response to dextroamphetamine in hyperactive boys.
The 24-hour urinary catecholamine metabolites 3-methoxy-4-hydroxyphenylglycol, normetanephrine, and metanephrine were measured in 23 hyperactive boys and 13 matched healthy controls. The hyperactive children excreted lower MHPG and higher NM (low MHPG/NM ratio) amounts than in controls. The administration of d-amphetamine in the dose of 0.5 mg/kg body weight divided over two doses daily for two weeks decreased MHPG excretion in the hyperactive children. When the hyperactive children group was divided into drug responders and nonresponders according to their pre- and post-treatment scores on the Conners Teacher Questionnaire, d-amphetamine administration decreased MHPG excretion in the responders and did not change it in the nonresponders. Percent decrease in MHPG excretion correlated significantly with percent change in the hyperactivity factor of the questionnaire on the Spearman Rank Order Correlation Coefficient. Pretreatment urinary metabolites did not differentiate the responders from nonresponders. It is suggested that a relationship between CNS norepinephrine metabolism and hyperactivity exists and that d-amphetamine may achieve its therapeutic action in hyperactive children by altering CNS NE metabolism.