Update and Practical Recommendations for the Use of Medical Treatment of Cushing Syndrome

Medical treatment of hypercortisolism may be necessary for a high proportion of patients with Cushing syndrome (CS), including those who are not candidates for curative surgery. It may also be used in the presurgical period when hypercortisolism is severe, as long-term treatment following surgical failure or recurrence after surgery, or while waiting for the effects of pituitary radiation in Cushing disease. Currently available medical treatments include adrenal steroidogenesis inhibitors that block cortisol secretion (ketoconazole, levoketoconazole, metyrapone, osilodrostat, mitotane, and etomidate), drugs that modulate pituitary ACTH secretion (pasireotide and cabergoline), and drugs that block peripheral glucocorticoid receptors (mifepristone). In addition, there are other medical treatments in development that target pituitary signaling pathways, ACTH or its adrenal receptor, or the conversion of cortisol from cortisone by 11ßHSD1. Steroidogenesis inhibitors can be administered using either a titration or a block-and-replace approach. Titration requires adjusting the daily drug dose with the aim of normalizing circulating cortisol levels, whereas the block-and-replace strategy uses higher drug doses to fully suppress endogenous cortisol production, followed by glucocorticoid supplementation. In this review, we summarize the main indications for medical treatment in CS, the mechanism of drug action, efficacy, recommended doses, and safety of the currently available drugs, as well as potential future treatments. We also discuss titration and block-and-replace approaches for control of hypercortisolism and provide recommendations for the use and monitoring of medical treatment in CS, including patients with endogenous hypercortisolism in special situations such as pregnancy, cyclic CS, and mild autonomous cortisol secretion.