Transdermal administration of oestrogen/progestagen hormone replacement therapy.

The effects of an oestrogen/progestagen transdermal therapeutic system (TTS) were evaluated in sixteen oestrogen-deficient women. The patients applied conventional oestradiol-TTS for 14 days, then two combined norethisterone acetate/oestradiol patches for a further 14 days. The treatment was repeated for five cycles. Ten patients then underwent metabolic studies. One patient had amenorrhoea, but the rest experienced regular withdrawal bleeding which was seldom heavy. Fourteen endometrial biopsy samples were taken during the fifth treatment cycle; none showed proliferative or hyperplastic features. The effects of transdermal norethisterone acetate on symptoms, lipid metabolism, and psychological status were determined by comparing features in the oestrogen-only phase and in the combined phase; the effects were very mild. These preliminary findings show that transdermal progestagen can be successfully administered in hormone replacement therapy to prevent endometrial proliferation while minimising the adverse effects that may be seen with oral administration.