17 beta-estradiol and norethisterone acetate in low doses as continuous combined hormone replacement therapy

To evaluate low doses of 17 beta-estradiol (E2) and norethisterone acetate (NETA) as continuous combined hormone replacement therapy (HRT) in their effects on vasomotor symptoms, bleeding episodes, endometrial histology and mastalgia.

Sixty postmenopausal women were randomly allocated to three treatment groups and were given 1 mg E2 and 0.25 mg NETA (A), 1 mg E2 and 0.5 mg NETA (B) and 2 mg E2 and 1.0 mg NETA (C) in daily doses. The treatment period was 1 year.

A similar statistically significant reduction of climacteric symptoms (P < 0.05) was found in all groups. Bleedings, mainly as spottings, occurred most commonly during the first treatment months. Fewer bleeding episodes and a higher percentage of amenorrhea was noted in group B compared to the other groups but did not reach statistical significance. All endometrial biopsies showed atrophy. Women in group A and B had less severe mastalgia (P < 0.05) compared to group C, given higher doses of steroids.

Postmenopausal women taking 1 mg of E2 plus 0.5 mg NETA as continuous combined HRT reported a marked reduction of climacteric complaints and good bleeding control. No endometrial proliferation was detected after 1 year of treatment. This type of therapy may be beneficial especially for elderly women, in whom bleeding may be annoying.