Successful Medical Adrenalectomy With Amino-glutethimide: Role of Altered Drug Metabolism

We used amino-glutethimide and dexamethasone in patients with carcinoma of the breast to abolish adrenal steroidogenesis. Initial studies with this approach, however, did not result in complete adrenal suppression and suggested the possibility of accelerated dexamethasone metabolism. The observation of a twofold reduction in H dexamethasone half-life during amino-glutethimide therapy confirmed this hypothesis. Larger doses of dexamethasone (1.5 to 3.0 mg/day) were administered to 22 patients receiving 1 to 2 gm of amino-glutethimide daily to compensate for rapid dexamethasone metabolism. Complete adrenal suppression for as long as 19 months was then observed, with objective tumor regression in eight subjects and relief of bone pain in three others without producing cushingoid side effects.