Placebo-controlled comparison of hormonal and biochemical effects of danazol and high-dose medroxyprogesterone acetate.

The hormonal and biochemical effects of danazol (600 mg a day) and high-dose medroxyprogesterone acetate (MPA; 100 mg a day) were studied in a placebo-controlled, 6-month trial. Serum gonadotrophins and prolactin levels did not change during danazol and MPA treatments, whereas oestradiol and progesterone levels decreased significantly in relation to placebo without any difference between danazol and MPA. Both drugs significantly suppressed the sex hormone-binding globulin level (SHBG), and consequently, the free-androgen index (serum total testosterone nmol/l per SHBG nmol/l x 100) as compared with placebo, the effect of danazol being significantly stronger than that of MPA. Danazol, but not MPA, significantly increased serum aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT) and haemoglobin levels, and also thrombocyte counts, whereas MPA, but not danazol, increased the serum concentration of albumin in relation to placebo. Serum total bilirubin, conjugated bilirubin, gamma-glutamyl transferase, creatinine, alkaline phosphatase, sodium and potassium levels and leucocyte counts remained unchanged during both treatments. Danazol and high-dose MPA did not differ from each other in their ovarian and anterior pituitary effects, while the increase in androgenic activity induced by danazol was greater than that achieved with MPA. Danazol also had more biochemical effects than MPA. It interfered with the functions of the liver and the production of thrombocytes and haemoglobin, whereas MPA affected only albumin synthesis/release.