Effect of Varying Doses of Methopyrapone (Metopirone) on the Secretion Rate of Cortisol

Abstract

Cortisol secretion rates were estimated in normal subjects given varying doses (250–1,000 mg) of methopyrapone (Metopirone) at varied time intervals (2, 4 or 6 hr) for 48 hr. The secretion rates were measured during the period 24–48 hr after commencing therapy, and in all studies, regardless of the dose of methopyrapone, the cortisol secretion rate remained within the range of normal basal levels. The relative quantity of tetrahydrodeoxycortisol (THS) produced was proportional to the dose of methopyrapone. These results are consistent with the hypothesis that, following 24 hr of methopyrapone administration, corticotrophin is released in quantities sufficient to maintain cortisol production at normal basal levels. There did not appear to be any advantage in administering methopyrapone more frequently than every 6 hr in a dose of 500 or 750 mg.