To study the long-term effects of bromocriptine on prolactin secretion, a group of patients was carefully evaluated (Fig. 4.16). Ten blood samples were taken from each patient before treatment; at three, six, and twelve months on therapy; and two months following drug withdrawal. All patients were treated with the same dose of bromocriptine (2.5mg three times per day). In all cases, bromocriptine lowered prolactin levels, and in nine of the twelve patients, prolactin secretion was suppressed throughout the year. After withdrawal of bromocriptine, prolactin levels rose in all patients to levels similar to those seen prior to therapy. The three patients in whom the prolactin levels were not lowered into the normal range, nevertheless, regained normal gonadal function.
