Efficacy and safety of ultra-low-dose estradiol and norethisterone in postmenopausal Brazilian women

Objective: This study aimed to evaluate the efficacy and safety of oral ultra-low-dose continuous combination of 17β-estradiol (17β-E2) and norethisterone acetate (NETA) in postmenopausal Brazilian women. Methods: Postmenopausal women (age 45–60 years) with amenorrhea >12 months and intact uterus, with moderate to severe vasomotor symptoms, were included. The vasomotor symptoms and endometrial bleeding were evaluated by a daily diary for 24 weeks, and the women were assessed at baseline and endpoint. Results: A total of 118 women were included. The group treated with 0.5 mg 17β-E2/0.1 mg NETA (n = 58) showed a percentage reduction of 77.1% in the frequency of vasomotor symptoms versus 49.9% in the placebo group (n = 60) (p = 0.0001). The severity score showed a reduction in the treatment group when compared to the placebo (p < 0.0001). The adverse events were comparable between the groups; however, in the 0.5 mg 17β-E2/0.1 mg NETA group there were more complaints of vaginal bleeding; despite that, in most cycles in both treatment groups, more than 80% of women experienced amenorrhea. Conclusions: The combination of 0.5 mg 17β-E2/0.1 mg NETA in a continuous combination regimen was shown to be effective in reducing the frequency and severity of vasomotor symptoms in Brazilian postmenopausal women.