POMC and Increased circulating aldosterone concentration: In keeping with the prednisone, 2.5 mg, twice daily and 5 mg once daily groups not meeting the primary end point for absence of mineralocorticoid excess toxic effects, plasma ACTH increased significantly during treatment from baseline to cycle 3 with abiraterone plus prednisone, 5 mg, once daily (median, 8.95 pmol/L; interquartile range [IQR], 4.39-12.63) (P < .001) and abiraterone plus prednisone, 2.5 mg, twice daily (median, 3.97 pmol/L; IQR, 0.42-9.24) (P < .001).