EFFECT OF ALPHA-METHYL-PARA-TYROSINE ON RESPONSE TO COCAINE CHALLENGE

This study evaluated the effect of an acute reduction in catecholamine synthesis produced by alpha-methyl-para-tyrosine (AMPT), a tyrosine h ydroxylase inhibitor, opt cocaine-induced euphoria. In a blinded, plac ebo-controlled study, AMPT (1 g p.o. T.I.D.) was given to 10 non-treat ment-seeking cocaine abusers prior to intranasal administration of 2 m g/kg cocaine, AMPT, but not placebo, reduced plasma levels of the dopa mine metabolite homovanillic acid and the norepinephrine metabolite 3- methoxy-4-hydroxyphenylglycol. AMPT also elevated prolactin levels, in dicating inhibition of the tuberoinfundibular dopamine system. AMPT pr etreatment produced a trend toward diminished cocaine ''high.'' AMPT a lso tended to lower heart rate and blood pressure responses to cocaine , but had no effect on serum cocaine levels. Although lye cannot rule out the therapeutic potential of the depletion strategy, our results w ith. AMPT alone, at this dose, do not strongly support it. (C) 1997 So ciety of Biological Psychiatry.