Bromocriptine therapy for non-functioning pituitary adenoma

Over a 6-year period, 25 patients with non-functioning pituitary adenomas were treated with bromocriptine, while 18 other patients with this condition underwent surgery as the first therapeutic modality. The medically treated group, consisting of those patients without alarming eye symptoms, was analysed in retrospect. Eight of these patients had previously undergone surgery and radiotherapy. Bromocriptine was used in a dose of 5 to 22.5 mg per day; the mean duration of treatment was 18 months. For 11 patients, radiological findings obtained during the year before treatment with bromocriptine revealed progression in five cases and stable tumour size in the others. Three of the five patients with progression showed tumour size reduction during bromocriptine therapy while no further growth occurred in the other two. When medication was stopped in one responding patient, the tumour grew again. One other patient, without pretreatment radiological investigation, exhibited tumour size reduction during bromocriptine therapy, and one patient exhibited radiological progression during the study period. In one case visual fields improved and in one other deteriorated without parallel changes in tumour size on computerized tomography. The favourable reactions were equally divided between the groups with and without previous radiotherapy. We conclude that bromocriptine is rarely capable of reducing the size of non-functioning pituitary adenomas (16% in this series). However, pituitary adenomas exhibiting recent growth may be sensitive to this drug, leading to size reduction or growth arrest.