Ultra-low-dose estradiol and norethisterone acetate: bleeding patterns and other outcomes over 52 weeks of therapy

Abstract

Background: Continuous combined hormone replacement therapy (HRT) with 0.5 mg 17β-estradiol (E2) + 0.1 mg norethisterone acetate (NETA) received marketing approval based on 24-week results. The current study collected data up to 52 weeks, including consideration of bleeding, a major reason for stopping HRT.

Methods: This 52-week (13 lunar-month), non-interventional, prospective study involved 169 women from Norway and Sweden receiving daily oral 0.5 mg E2 + 0.1 mg NETA to treat menopausal symptoms. Incidences and cumulative rates of amenorrhea (no bleeding or spotting) and no bleeding (women could have spotting) were evaluated, together with hot flushes and quality of life.

Results: Overall, > 78% and > 90% of subjects were amenorrheic or had no bleeding, respectively, in each of the first 3 lunar months, while > 88% and > 96% were amenorrheic or had no bleeding, respectively, in each of lunar months 10, 11 and 12. Cumulative rates of amenorrhea and no bleeding were 67% and 83%, respectively, in lunar months 1-3, and 84% and 94%, respectively, in lunar months 10-12. The number of hot flushes declined during treatment (means at weeks 1, 12 and 52, respectively: 15.5, 5.0 and 4.1 [mild]; 19.0, 3.0 and 2.3 [moderate]; 10.8, 1.1 and 0.9 [severe]). Improvement in all four domains of the Menopause-Specific Quality of Life-Intervention questionnaire (vasomotor, psychosocial, physical and sexual) was evident by week 26.

Conclusion: For women receiving 0.5 mg E2 + 0.1 mg NETA, lack of bleeding-related side-effects, together with beneficial effects on hot flush symptoms and quality of life, may promote treatment continuance.

Keywords: BLEEDING; CONTINUOUS COMBINED HORMONE REPLACEMENT THERAPY; ESTRADIOL; HOT FLUSHES; MENOPAUSE; NORETHISTERONE ACETATE; QUALITY OF LIFE; ULTRA-LOW-DOSE.