Medical treatment of Cushing's disease

Cushing's Syndrome (CS) is a serious endocrine disease that results from the adverse clinical consequences of chronic exposure to high levels of glucocorticoids. Most patients with endogenous CS have an adrenocorticotropin (ACTH)-secreting pituitary corticotroph adenoma, i.e. Cushing's Disease (CD). The first-line therapy for CD is transsphenoidal pituitary surgery. If tumor removal is incomplete or unsuccessful, persistent hypercortisolism will require further treatment. Repeat surgery, medical therapy, radiation and bilateral adrenalectomy are all second line therapy options; however, medical therapy can be also used as first line therapy in patients who cannot undergo surgery, or to decrease Cortisol values and/or improve co-morbidities. Medications used in the treatment of CD, classified into three groups: pituitary directed drugs, adrenal steroidogenesis inhibitors and glucocorticoid receptor blockers, are reviewed. Future 'on the horizon' treatment options are also discussed.