Pharmacological treatment for pituitary adenomas

Abstract

Hitherto, surgical resection has been the best treatment for clinically non-functioning pituitary adenoma, because an effective drug is not available. In patients with growth hormone (GH), adrenocorticotropic hormone (ACTH) or thyroid-stimulating hormone (TSH) producing pituitary adenomas, the first-line treatment is surgical intervention too. However, recent pharmacological treatment has proved effective against functioning pituitary adenomas. As certain recent dopamine agonists are very effective against prolactinoma, a pharmacological approach has become the first- line for treatment of prolactinoma. Dopamine agonists have high normalization rate of hyperprolactinemia; however, its cure rate remains unsatisfactory. In acromegaly patients, a long-term surgical cure rate of ca. 70%. Therefore, a chemotherapeutic approach may play an important complementary role in achieving complete treatment of acromegaly. But the efficacy rate of somatostatin analog for acromegaly is ca. 70%. Pegvisomant can also control IGF-I levels; however, complete cure of acromegaly has yet to be established. Cushing's disease, which is associated with high morbidity and mortality, is a life-threatening disease in patients where hyper corti solemia cannot be controlled. In cases where surgical treatment has failed, medical management is essential for reducing or normal izing—hyper cortisolemia. Mitotane and methyrapone are effective drugs for hyper cortisolemia; however, a useful candidate for ACTH-producing pituitary adenoma has yet to be established. For aggressive pituitary tumors such as atypical pituitary adenoma and pituitary carcinoma, the use of temo-zolomide was attempted.