A randomized comparative study of the effect of leuprorelin acetate depot and danazol in the treatment of endometriosis

BACKGROUND: Administration of superactive agonistic analog of gonadotropin-releasing hormone (GnRH) has shown to induce a paradoxic and reversible suppression of gonadotropins, so that gonadal steroid concentrations are suppressed and hypoestrogenemia is induced. In order to compare the efficacy and safety of leuprorelin acetate depot (LA) and danazol in the treatment of endometriosis, we conducted this study. METHODS: A total of forty-five patients with pelvic endometriosis of different severity at laparoscopy with biopsy of peritoneal implants (n = 33) and surgical procedure (enucleation of ovarian chocolate cysts, cystectomy, or fulguration, n = 12) were included in the study and followed during the 20 weeks of treatment. LA 3.75 mg was injected subcutaneously every 28 days, while the daily oral dose of danazol was 800 mg. RESULTS: Both treatments were associated with a lowering of severity score. There was a consistent decrease in women with stage IV disease in the LA group and an increase in patients with stage I disease in the danazol group, but no difference was found between both treatments. Hot flushing was the most common side effect reported in 97% of LA but occurred only in 13% of danazol-treated patients. In contrast, the androgenic, anabolic side effects of weight gain and myalgia were common in those receiving danazol. The CA-125 levels were significantly lower in both treatment groups compared with their pretreatment levels (p < 0.01). During the five months of the LA treatment, biochemical evaluation revealed no pathologic alternation. Only total protein albumin, alkaline phosphatase, total bilirubin, total cholesterol, high density lipoprotein-cholesterol, low density lipoprotein-cholesterol, uric acid and calcium increased significantly. Danazol was also associated with adverse metabolic effects and significantly increased low-density lipoprotein-cholesterol concentrations (p < 0.05). In the fourth week, serum estradiol (E2) levels decreased to nearly castrated levels (13.87 +/- 1.63 pg/ml) in all patients treated with LA, and remained at this level thereafter. On the contrary, a slight but significant increase of the serum E2 levels was noted during the danazol treatment. After five months of treatment with LA, no significant changes in bone density were observed at the femoral neck or the anteroposterior (AP) view of lumbar spine, but there was a significant loss in bone density at the lateral view of lumbar spine (-7.1%, p < 0.05). CONCLUSIONS: Both LA and danazol are effective in the treatment of endometriosis. The hypoestrogenic side effects of LA may be better tolerated than the androgenic, anabolic effects of danazol. However, the danazol treatment costs less than LA and has no significant side effect with osteoporosis.