Further studies on the effects of flutamide on cortisol metabolism

Flutamide (4'-nitro-3'-trifluoromethylisobutyranilide) has a pronounced effect on the delta 4-3-ketosteroid 5-reductases of cortisol in man. The urinary metabolites isolated following 4-14C-cortisol administration to men with prostatic cancer treated with flutamide indicate decreased activity of the 5 beta-reductase with increased activity of 5 alpha-reductase. The alternate pathway of cortisol metabolism to the cortols and cortolones via Reichstein's substances epi E and Epi U is enhanced.