[Dihydroergotoxine mesylate in the treatment of functioning pituitary adenoma]

Although it is well known that bromocriptine (BC) is effective in the treatment of functioning pituitary adenoma, this agent sometimes causes severe gastrointestinal side effects. In this study, dihydroergotoxine mesylate (EX), which is composed of ergot alkaloids and is similar to BC, was administered to 11 patients with functioning pituitary adenomas who could not tolerate the adverse effects of BC. Three patients (27%) showed clinical improvement with EX treatment alone (1 to 6 mg/day). In another patient, computed tomography demonstrated tumor shrinkage. The remaining seven patients experienced adverse effects while taking EX. These results indicate that EX is a useful alternative to BC in the treatment of functioning pituitary adenoma, particularly in patients who cannot tolerate the side effects of BC. Moreover, pretreatment with EX appears to reduce the incidence of side effects of BC.