Efficacy and safety of bromocriptine in the treatment of macroprolactinomas

To assess the effectiveness of bromocriptine (BRC) as primary therapy in reducing the size of PRL-secreting macroadenomas with extra-sellar extension, we conducted a multicenter study in 29 patients without prior radiotherapy. Clinical presentation, response to medical treatment and long term follow-up of 29 patients with macroprolactinoma (pituitary mass more than 10 mm in diameter) were analysed. There were 19 women for 10 men. Mean age was 33 years. An hypogonadism was present in 94% of women vs 57% for men. Headaches and or visual abnormalities were present in 68% of women vs 90% of men. The mean basal serum prolactin level before treatment was 1 501 ng/ml: 202 ng/ml for women (range: 70-478 ng/ml) and 3 870 ng/ml for men (range: 100-20 476 ng/ml) and was correlated to tumoral size. 25 patients were treated with BRC as primary therapy with a mean dose of 9,7 mg/day (13 mg/day in men and 8 mg/day in women). BRC no malized serum PRL levels in all men and in 17/19 women over a mean period of 6 months, ranging from 3 to 72 months in both sexes. Tumor size was reduced by more than 50% in 18/29 patients (62%) with secondary empty sella in 5 patients and by less than 50% in 11 patients. Visual field improved in most of the patients in whom it was initially abnormal. Reduction in size was quite fast in most of patients but slower in some of them. The cumulative radiological response to BRC increased with time. Therefore, it appears that prolonged medical therapy is effective and safe in macroprolactinomas.