Long-term treatment of idiopathic hyperaldosteronism using trilostane

Three patients with idiopathic hyperaldosteronism were continuously treated with trilostane, a competitive inhibitor of adrenal 3 beta-hydroxysteroid dehydrogenase (3 beta-HSDH) (3 to 4 2/3 years). Trilostane, in conjunction with antihypertensive drugs, effectively decreased plasma aldosterone levels and improved hyperaldosteronism symptoms without undesirable side effects. Trilostane continued to be effective even when treatment was continuous. Rapid ACTH testing (iv bolus of 0.25 mg alpha 1-24 ACTH) was done on the day without trilostane after long-term treatment, and plasma levels of aldosterone and cortisol were compared to those obtained during a pre-treatment period. Results suggest that the inhibitory effect of trilostane on steroid biosynthesis rapidly disappears following discontinuance of trilostane administration even after long-term treatment, and that continuous treatment causes no significant or irreversible change in steroid biosynthesis. These results suggest that trilostane is a safe, feasible therapeutic agent for long-term treatment of idiopathic hyperaldosteronism.