D-FENFLURAMINE-INDUCED PROLACTIN RESPONSES IN POSTWITHDRAWAL ALCOHOLICS AND CONTROLS

Serum prolactin response to the serotonin agonist D-fenfluramine were measured in 19 DSM-111-R male alcoholics, 2.5 or more weeks postalcoho l withdrawal, Prolactin responses were compared with nine healthy nona lcoholic male controls, After an overnight fast, each subject received 30 mg of D-fenfluramine orally, and serial samples of serum prolactin were taken over a 4-hr period, D-fenfluramine caused a significantly attenuated peak g-prolactin response in the alcoholics relative to the controls (p = 0.05), A repeated-measures ANOVA of delta-prolactin yie lded a significant within-subjects effect of time (p < 0.05), a within -subjects effect of group that reached significance (p = 0.05), and a nonsignificant group by time interaction. The delta-prolactin value at time points 60 and 240 min postadministration of the probe was signif icantly attenuated in the alcoholic group, with p < 0.05, There was al so some evidence for a diminished serotonergic response in those alcoh olics with a negative family history, The delta-prolactin response did not correlate with subjects' age, duration of alcohol use, duration o f abstinence from alcohol, severity of alcohol dependence, or age of o nset. Results imply a relative subsensitivity of the serotonin system in postwithdrawal alcoholics, and this may be primarily of the 5-HT2 r eceptor.