Additive effect of ketoconazole and octreotide in the treatment of severe adrenocorticotropin-dependent hypercortisolism.

Over the last few years ketoconazole and octreotide have been employed in the treatment of pituitary-dependent or ectopic Cushing's syndrome. In four patients (two men and two women, aged 25-64 yr) with severe ACTH-dependent hypercortisolism in whom medical treatment with ketoconazole showed limited effectiveness and/or tolerability, we tried the association with octreotide. In all patients ketoconazole (200-1000 mg) induced a marked decrease in urinary free cortisol (UFC) excretion, but normalization could not be achieved. After ketoconazole discontinuation, three patients received octreotide alone (300-1500 micrograms/day, sc). This drug caused a dramatic decrease in UFC excretion, although not normalization; in all patients, escape from treatment occurred. Combined treatment was carried out for 10-180 days. Urinary cortisol excretion normalized and remained steadily within normal limits in three of four patients in whom normal UFC excretion had never been attained with both single drug regimens; in the fourth patient, UFC excretion decreased to levels lower than those achieved with ketoconazole or octreotide alone. The association with octreotide allowed a reduction in the daily dose of ketoconazole in three patients. Consistent with the steady reduction of cortisol production, a striking clinical improvement occurred in all patients after starting combined treatment. The normalization of UFC in three of four patients treated with both agents suggests that this approach may be useful in the long term treatment of severe forms of hypercortisolism of both pituitary and ectopic origin. In contrast to the limited effectiveness of each drug taken singularly at the same or higher doses, the association of the two drugs had an additive effect in the attainment of normal urinary cortisol excretion.