Serum prolactin and ovarian function after discontinuation of drug treatment for hyperprolactinaemia: a study with bromocriptine and metergoline.

Serum prolactin (PRL) was estimated for up to 2 months after discontinuation of therapy with either bromocriptine (n = 33; 15 with idiopathic disease, 12 with pituitary microadenoma, and six with macroadenoma) or metergoline (n = 23; 11 with idiopathic disease, and 12 with microadenoma) that had been administered for 8-30 months. Only five patients treated with bromocriptine and two treated with metergoline had PRL levels that remained normal or below 50% of pretreatment values. Among the patients followed-up for up to 12 months, four showed a fall in PRL at 3-4 months, but this was followed by a rise in one patient. Five patients showing persistently lower or normal PRL after drug withdrawal were retested with thyrotrophin-releasing hormone; the two responsive women also had a normal response before treatment. Of 10 patients followed for 9 months, three had persistently normal PRL levels. Amenorrhoea and anovulation recurred, with some delay, in all the patients showing PRL rebound except one. Medical treatment of hyperprolactinaemia only rarely results in permanent benefit.

Spontaneous and induced pregnancies in hyperprolactinemic women.

Sixty-nine pregnancies were observed in 57 hyperprolactinemic women (5 with pituitary macroadenoma, 20 with microadenoma, and 32 with normal tomography of the sella turcica). Ten of these pregnancies took place spontaneously in women with mild to moderate hyperprolactinemia (up to 70 ng/ml); 2 were induced by exogenous gonadotropins, 2 by clomiphene, 42 by bromocriptine, and 9 by metergoline; and 4 occurred after pituitary selective adenomectomy. The observed complications included spontaneous abortion (10 cases); headache (7 cases); sellar enlargement (5 cases); and bitemporal hemianopsia (1 subject with macroadenoma). Among 24 women in whom prolactin levels were reevaluated at least 1 month after parturition and/or lactation, 8 showed a decrease in prolactin concentration (less than 50% of pregestational levels), with actual prolactin normalization in 3 and resumption of cyclic menses in 2 previously amenorrheic women. In contrast, no changes in prolactin levels occurred after pregnancies that ended in abortion. These data suggest the following: 1) conception is not uncommon in women with moderate hyperprolactinemia; and 2) pregnancy may be safely induced without prior surgery and/or radiotherapy in hyperprolactinemic women, except those with large pituitary adenomas, and a considerable number of these patients even show a clinical and biochemical improvement after pregnancy.

Failure of nomifensine administration to discriminate between tumorous and nontumorous hyperprolactinemia.

It has recently been claimed that the PRL-lowering response to nomifensine administration (200 mg, orally) reliably discriminates patients with PRL-secreting tumors from those with so-called functional hyperprolactinemia. In the present study, this test was performed in 15 healthy controls, 7 hyperprolactinemic subjects without evidence of pituitary tumor, and 16 patients with prolactinoma. A decrease of serum PRL to below 65% of basal levels, which seemed to be the cut-off point in the previous study, was obtained in 11 subjects of the first group, in 4 subjects of the second group, and in 4 subjects of the third group. The decrease of mean serum PRL concentration after nomifensine was only significant in the first and second groups. Analysis of variance showed a significant difference in the PRL inhibition by nomifensine between the tumor group and the two groups without evidence of pituitary adenoma. Nevertheless, this study shows that the nomifensine test is unable to discriminate in the individual patient the tumorous or nontumorous origin of excessive PRL secretion.