Evaluation of Effects of Letrozole Compare to Danazole in Patients Confirmed Endometriosis: A Randomized Clinical Trial

Abstract

Background: Letrozole is an aromatase inhibitor which can decrease estrogen production in peripheral tissues and endometriosis. Danazole, as an androgen, inhibits estrogen production in ovaries and recently has been introduced as an aromatase inhibitor; this study was designed to compare the effects of danazole with letrozole to relieve symptoms of endometriosis. Methods: In this randomized clinical trial study, 105 patients confirmed endometriosis by laparoscopy. These patients were randomly assigned to three groups: group 1 received letrozole tablet (2.5 mg/day), calcium (1000 mg/day) and vitamin D (800 IU/day), group 2 received danazole tablet (600 mg/day), calcium (1000 mg/day) and vitamin D (800 IU/day) and group 3 (placebo group) received calcium (1000 mg/day) and vitamin D (800 IU/day). Pelvic pain, dysmenorrhea and dyspareunia were assessed in participants before study and monthly during the study for six months. Data were analyzed via SPSS15 software with Freidman and Wilcoxon tests. Findings: Mean age was not statistically different in three groups. Totally, 105 participants were enrolled in this study; 38 patients in letrozole group, 37 patients in danazole group and 31 patients in placebo group. In letrozol group, the mean of chronic pelvic pain, dysmenorrhea and dyspareunia score were less than danazole and placebo groups. The Wilcoxon test showed significant difference between mean of dysmenorrhea score at the 5th month after treatment compare to the 1st month in letrozol group (P = 0.025). Conclusion: This study showed that letrozole is more effective than danazole in relief chronic pelvic pain, dyspareunia and dysmenorrhea. Keywords: Letrozole, Danazole, Endometriosis, Laparoscopy.