Metyrapone test in Cushing's disease.
The urinary 17-hydroxycorticosteroid response to 2 g of metyrapone given orally at 10 PM was compared with that following the standard test in which 750 mg of metyrapone was given at 4 hourly intervals for 6 doses. Both tests were performed on four occasions in 3 patients with Cushing's disease. Increments in urinary 17-hydroxycorticosteroid excretion during the modified test were 7.0, 7.5, 8.4 and 23.3 mg/day, whereas with the standard test, increments ranged from 29.5 to 56.8 mg/day. The urinary 17-hydroxycorticosteroid response to the 2 g dose of metyrapone at 10 PM was marginal in 3 of the 4 studies. Urinary 17-hydroxycorticosteroid excretion with the modified metyrapone test varied from 10.7 to 44% of that found with the standard test. Since urinary steroid excretion may vary considerably in patients with Cushing's syndrome as was evident in 2 of the 3 patients studied, the data suggest that the modified metyrapone test should not be used in preference to the standard test in evaluating Cushing's syndrome. It appears that the modified test could lead to erroneous conclusions.
D015065:17-Hydroxycorticosteroids / Q000652:urine; D000284:Administration, Oral; D000328:Adult; D003480:Cushing Syndrome / Q000503:physiopathology*; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D008297:Male; D008797:Metyrapone / Q000008:administration & dosage; D008875:Middle Aged; D010912:Pituitary-Adrenal Function Tests / Q000379:methods*; D010913:Pituitary-Adrenal System / Q000503:physiopathology*
D015065:17-Hydroxycorticosteroids; D008797:Metyrapone