The use of the glucocorticoid receptor antagonist mifepristone in Cushing's syndrome.

Mifepristone is the first and only available glucocorticoid receptor antagonist. Cushing's syndrome is a rare disease, responsible for increased morbidity and mortality. The treatment of Cushing's syndrome is far from perfect. The aim of this review is to better define the merits and pitfalls of mifepristone in treating Cushing's syndrome, and try to determine its potential roles in the treatment of hypercortisolism. Only case reports or series based on a low number of patients had been reported in the literature. A recent retrospective European Study based on about 20 patients with Cushing's syndrome gave more precise data about mifepristone. Coupled with the 20 previously reported patients in various studies, these results determine the profile of patients who could benefit from mifepristone. High clinical efficacy of mifepristone is counterbalanced by the lack of available biological monitoring data during treatment, and the risk of worsening of hypokalemia and blood pressure levels. However, its rapid efficacy and the fact that the drug uses a mechanism that is different from all currently available treatment should make mifepristone a valuable treatment in particular cases of uncontrolled hypercortisolism despite classical methods.