Genital Bleeding during the Administration of Danazol

Abstract In an effort to reduce undesirable bleeding during danazol treatment, we attempted to see any correlation between the frequency of bleeding and the starting period of danazol treatment during the menstrual cycle. We studied 57 women who were suffering from endometriosis externa and given danazol (400 mg/day) for periods between 16 and 24 weeks. The patients were divided into 4 groups depending on the day administration of the drug began; 18 patients started on the 1st or 2nd day of the menstrual cycle, 12 on the 3rd day, 20 on the 5th day and 7 after the 10th day. The rate of bleeding was 6.8±6.3% (M±SD) in the group starting on the 1st or 2nd day. This was significantly smaller than that of other groups starting treatment later in the menstrual cycle. The number of patients with complete amenorrhea throughout the entire treatment period was significantly higher in the group beginning administration of danazol on the 1st or 2nd day of the menstrual cycle. Therefore, administration of danazol should be started as early as possible in the menstrual cycle to reduce the frequency of bleeding.