Effects of single and multiple doses of ketoconazole on adrenal function in normal subjects.

The plasma cortisol response to 0.25 mg tetracosactrin given by intramuscular injection was suppressed by nine oral doses of 200 mg ketoconazole given 12 hourly to nine normal female subjects. No effect was noted following a single 200 mg oral dose of ketoconazole. This suppressive effect was reversible within at least 5 days of discontinuation of ketoconazole.