A randomized, parallel, comparative study of the efficacy and safety of nafarelin versus danazol in the treatment of endometriosis in Taiwan.

BACKGROUND The purpose of this study was to evaluate the efficacy and safety of nafarelin, a gonadotropin-releasing hormone (GnRH) analogue, versus danazol in the treatment of women with endometriosis in Taiwan. METHODS Fifty-nine women with laparoscopically and pathologically confirmed endometriosis were randomized to receive nafarelin or danazol for 180 days. Efficacy was assessed from mean changes in laparoscopy score (LS) and total symptom severity score (TSSS). Adverse events (AEs) and laboratory parameters, including hematology, hepatic function, blood pressure, and lipid levels, were monitored for safety evaluations. RESULTS All demographic and baseline factors, except body weight, were comparable between the 2 treatment groups. Both nafarelin and danazol satisfactorily resolved pelvic tenderness, induration, pelvic pain, dysmenorrhea and dyspareunia. No significant differences were noted in efficacy endpoints between nafarelin and danazol regarding LS and TSSS at 90 and 180 days of treatment. No significant difference was observed between the 2 groups regarding the overall incidence of AEs, except for laboratory-related AEs. However, nafarelin tended to have less impact than danazol on aspartate transaminase and alanine transaminase, and nafarelin was better tolerated than danazol regarding changes in lipid profiles. Both treatments had little or no effect on hematologic parameters. CONCLUSION Nafarelin and danazol demonstrated similar clinical efficacy, but nafarelin was associated with fewer laboratory changes and a stable lipid profile, relative to danazol. Moreover, intranasally administered nafarelin is noninvasive, and may be a more comfortable and safer alternative to slow-release injectable GnRH agonists. Based on this study, we suggest that nafarelin, like other GnRH analogues, may be a treatment of choice for Taiwanese women with endometriosis. However, direct comparative studies of nafarelin with slow-release injectable GnRH agonists are now required.