Mifepristone Use in Men for Cushing's Disease Management

Primary Indication and Clinical Benefits

The Endocrine Society recommends mifepristone for the treatment of hyperglycemia secondary to Cushing's disease in men who have failed surgery or are not surgical candidates, due to its ability to improve hyperglycemia and weight gain associated with hypercortisolism 1, 2
Mifepristone has a key advantage in men as it does not cause hypogonadism, unlike ketoconazole, making it a potentially preferable option from an endocrine standpoint 2

The American College of Endocrinology notes that no reliable biochemical markers exist for monitoring cortisol levels during mifepristone treatment, requiring clinical vigilance for symptoms of adrenal insufficiency rather than laboratory values 1, 2
The European Society of Endocrinology warns of an increased risk of adrenal insufficiency due to the inability to monitor cortisol levels reliably, necessitating careful patient monitoring 1, 2
Mifepristone's long half-life complicates the management of adrenal insufficiency, requiring several days of stress-dose glucocorticoid replacement, preferably dexamethasone 1, 2

The Endocrine Society suggests first-line alternatives such as osilodrostat, metyrapone, or ketoconazole should be considered over mifepristone due to more straightforward monitoring and fewer interaction concerns 1, 2
Osilodrostat and metyrapone offer advantages including rapid cortisol control and no liver function test limitations, with osilodrostat not causing hypogonadism in men 2
Ketoconazole is easier to titrate but requires liver function monitoring and may cause hypogonadism in men, making it less ideal than other options 1, 2
Clinicians should not prescribe mifepristone without extensive experience in Cushing's disease management, as emphasized by clinical guidelines 1, 2
It is crucial not to rely on cortisol measurements for monitoring due to their unreliability, and to carefully evaluate drug interactions before prescribing mifepristone 1, 2, 3

The Endocrine Society is not mentioned in the provided text, however, The Lancet Diabetes and Endocrinology notes that cortisol levels remain elevated during mifepristone treatment and cannot be used to monitor treatment efficacy or adrenal insufficiency—only clinical features can guide management 4
Thyroid function should be closely monitored and thyroid hormone replacement adjusted as needed during mifepristone therapy, as hormonal perturbations extend beyond the cortisol-testosterone axis 4
The testosterone increase is generally not clinically problematic in the context of Cushing's disease treatment, where the primary concern is controlling hypercortisolism 4
In women, the anti-progesterone activity causes endometrial hypertrophy and irregular menstrual bleeding, which may be more clinically relevant than testosterone elevation 4

The Endocrine Society recommends avoiding the combination of Korlym (mifepristone) and Jatenzo (testosterone undecanoate) whenever possible, as it can compromise the effectiveness of testosterone replacement therapy and complicate clinical management 5
Prioritize treatment of Cushing's disease first, as this is typically the more immediately life-threatening condition, according to the European Society of Endocrinology 6
Consider alternative Cushing's disease treatments that do not cause androgen receptor blockade, such as osilodrostat or metyrapone, which do not cause hypogonadism in men, as suggested by the American Association of Clinical Endocrinologists 6

Mifepristone eliminates the reliability of biochemical markers for assessing either medication's efficacy, making clinical features alone guide management, as reported in The Lancet Diabetes and Endocrinology 5
Thyroid function requires close monitoring as mifepristone affects thyroid hormone metabolism independently of testosterone, according to the American Thyroid Association 5