Nomifensine: diagnostic test in hyperprolactinemic states

Nomifensine, an antidepressant agent which activates dopamine (D) neurotransmission mainly by inhibiting DA reuptake in the central nervous system, was administered either to puerperal lactating women or to subjects with nonpuerperal hyperprolactinemia. In 10 postpartum women and in 7 women with no evidence of PRL-secreting tumor, oral administration of nomifensine (100 or 200 mg, respectively) induced in the following 5 h a clear-cut inhibition of plasma PRL levels; in 10 patients with PRL-secreting tumors, the drug did not lower plasma PRL levels. In 2 of these patients nonsupressibility of plasma PRL levels to nomifensine was the only indication of the existence of a pituitary microadenoma. It is proposed that acute nomifensine testing may be a valid neuropharmacological tool for discriminating between individuals with and without pituitary adenoma.