Use of a compound of formula (I) or a 3-enol C1-4 alkanoate ester thereof in the manufacture of a medicament for the intermittent treatment of a condition of a human or non-human mammal in which said mammal has an abnormally high serum concentration of an adrenal hormone: Wherein R1, R2, R5, and R6 are the same or different and each is hydrogen or C1 to 4? alkyl; R3 is hydrogen C1 to 4? alkyl, C1 to 4? alkenyl or C1 to 4? alkynyl; R4 is hydroxy, C1 to 4? alkanoyloxy, a group of formula (II) or (III) Wherein R7 is (CH2)n, where n is an integer of from 0 to 4, R8 is hydrogen, C1 to 4? alkyl, hydroxy or NH2 and R9 and R10 are the same or different and each is hydrogen or C1 to 4? Alkyl; or R3 and R4 together are oxo, ethylenedioxy or propylenedioxy. The invention has practical benefits for the treatment of man and other animals with diseases associated with abnormal production of adrenal steroids. The invention also shows that sustained suppression of the adrenal hormones is not required to achieve relief of symptoms in these conditions.