Effects of transdermal oestrogen therapy in postmenopausal women: a comparative study of an oestradiol gel and an oestradiol delivering patch

Objective To compare the efficacy, safety and tolerability of an oestradiol gel (1.0 mg of oestradiol daily, Divigel®/Sandrena®) with those of an oestradiol delivering patch (delivering 50 μg oestradiol/24 h, Estraderm TTS®) in hormone replacement therapy of postmenopausal women. Dydrogesterone tablets (Terolut®), 10 mg daily for the first 12 days of every month, were used as the progestogen component of the therapy. Main outcome measures The effect of treatment on clinical symptoms and on endometrium, total body bone mineral density and lipid metabolism as well as the tolerability of the treatments with special emphasis on skin irritation and compliance were evaluated. Design An open, randomised, controlled, parallel-group trial of 12 months duration. Setting The Medical Clinic of Kalevankatu, Helsinki, Finland. Participants One hundred twenty postmenopausal women were treated with transdermal oestradiol combined with dydrogesterone. In addition, 25 women without HRT served as a reference group for the bone mineral density measurements. Results Both treatment regimens were equally effective in alleviating climacteric symptoms, preserving bone mineral density and were equally safe. A trend towards heavier bleeding was detected in patients treated with the oestradiol delivering patch. A statistically nonsignificant decrease of total cholesterol and triglyceride concentrations but no change in high-density lipoprotein cholesterol concentration was observed in both groups. The acceptability of the treatment was higher in the gel group (96.4%) than in the patch group (90.7%). Only two (3.3%) women using the oestradiol gel complained of skin irritation whereas 28 patients (46.7%, P<0.001) using the oestradiol delivering patch reported this adverse effect. Conclusions Both the oestradiol gel and the oestradiol delivering patch are equally effective in hormone replacement therapy but the gel preparation is less irritative to the skin.