NORMALIZATION BY BROMOCRIPTINE OF THE ABNORMAL PRL RESPONSE TO TRH INABSTINENT COCAINE ADDICTS

This study was performed to establish possible alterations of the dopa minergic inhibitory control of prolactin (PRL) secretion in cocaine ad dicts during abstinence, when the effects of acute cocaine assumption or the neuroendocrine changes associated with drug withdrawal had ceas ed. For this purpose, 18 cocaine addicts (according to the DSM III R c riteria) admitted to a recovery community for drug abusers were random ly divided into two groups, matched for age (group I (range): 20-37 yr ; group II: 21-38 yr), weight (group I: 74.1 +/- 7.1 Kg (mean + S.E); group II: 73.8 +/- 8.3 Kg) and duration of drug abuse (group I: 24-48 months; group II: 24-48 months). The two groups were tested twice with TRH (200 mu g in an i.v. bolus), once after 15 days of abstinence and again after 15 days of oral treatment with 5 mg/day bromocriptine (gr oup I) or placebo (group II). A control TRH test was performed in 10 h ealthy men (age: 20-39 yr; weight: 75.6 +/- 6.1 Kg). Before bromocript ine or placebo treatment, basal and TRH-stimulated PRL, levels were si gnificantly higher in cocaine addicts than in normal controls. Placebo administration did not change the PRL secretory pattern in group II, whereas the administration of bromocriptine normalized both the basal levels of PRL and the PRL response to TRH. These data show increased P RL secretion in abstinent cocaine addicts, suggesting a reduced dopami nergic control of PRL secretion in these subjects. It is hypothesized that this neuroendocrine alteration might represent a trait marker of cocaine addiction, or more likely, that it was a consequence of a long addiction to cocaine persisting after one month of abstinence.