Prolactin secretion and menstrual function after long-term bromocriptine treatment.

Long-term bromocriptine treatment was discontinued in 75 hyperprolactinemic women. Bromocriptine had been given for up to 65 months (median, 24 months). Treatment was reinstituted in 42 women (56%) after 1 to 3 months, mainly because of increasing prolactin levels. Thirty-three women (44%) were followed up for 6 months or more without treatment. Menstrual bleeding occurred in 19 of the 33 women (58%) after 6 months without treatment. The mean prolactin concentration in this group had decreased more than 60% compared with pretherapy concentrations. In 18 of the 42 women who had bromocriptine therapy again, treatment was discontinued a second time. Six of these patients have regular menstrual bleeding. Long-term bromocriptine treatment seems to induce long-standing normalization of prolactin secretion in patients with hyperprolactinemia.