The impact of hypercortisolism on multiple metabolic conditions is well recognized; the metabolic manifestations of Cushing's syndrome overlap with those seen in type 2 diabetes and the metabolic syndrome. Ketoconazole (KTZ), a widely used antifungal agent that inhibits various enzymes in adrenal cortisol synthesis, is effective in treating hypercortisolemia, but its use is limited by toxicities. KTZ is a racemic compound of two cis-enantiomers: (2R,4S)-(+)-KTZ and (2S,4R)-(-)-KTZ. The consideration of an enantiomer with selective effect but minimal metabolic toxicity has driven the development of DIO-902 ([2S,4R]-[-]-KTZ) for the treatment of patients with type 2 diabetes and the metabolic syndrome. To evaluate the safety profile and effect of KTZ enantiomer, (2S,4R)-(-)-KTZ, on cortisol production, glycemia, and lipid profiles in patients with type 2 diabetes. Review of multiple published studies and examination of preliminary results from a Phase IIb clinical trial. Twelve weeks of treatment with DIO-902 resulted in reduced levels of HbA1c, FPG, total and LDL cholesterol as well as weight loss and decreased BP. In a previously conducted Phase IIa study, C-reactive protein levels decreased with DIO-902 treatment. Unfortunately, the development of this agent has been terminated due to unacceptable safety profiles.