CLINICAL TRIAL OF a NEW ORAL CONTRACEPTIVE PILL CONTAINING THE NATURAL OESTROGEN 17β‐OESTRADIOL

Abstract

The natural oestrogen, 17P-oestradiol, has been shown not to depress fibrinolysis and apparently has less influence on liver function and lipid metabolism than ethinyl oestradiol, the synthetic oestrogen in conventional 'combined' oral contraceptive tablets. A triple-blind study was therefore made of 21 5 women during 2051 treatment cycles with oral contraceptives containing either (i) 4 mg of micronized 17p-oestradiol and 3 mg norethisterone (Netagen 403), (ii) 4 mg 17P-oestradiol plus 2 mg of oestriol and 3 mg norethisterone (Netagen 423) or (iii) 50 pg ethinyl oestradiol and 3 mg norethisterone (Netasyn). There were no pregnancies or thrombotic incidents. The numbers discontinuing treatment were about the same in the three groups, the main reasons being intermenstrual spotting in those on Netagen 423, amenorrhoea and weight gain in those on Netagen 403 and nausea and weight gain in those on Netasyn. The natural oestrogen showed promise as a new and safe component of the 'combined' pill.

Evaluation of a new estradiol oral contraceptive: estradiol valerate and dienogest

“…Readers are referred to Pipeline (http://informa-pipeline.citeline.com) and Citeline (http://informa.citeline.com). abandoned because of a high incidence of irregular bleeding [8]. In 1980, the World Health Organization (WHO) Task Force on Oral Contraception reported a significantly higher incidence of problematic menstrual irregularities among subjects randomized to a norethisterone acetate OC formulated with 'natural' estrogen (micronized E 2 4 mg plus estriol (E 3 ) 2 mg) compared with those receiving EE (50 µg) [9].…”

Effects of a monophasic combined oral contraceptive containing nomegestrol acetate and 17β-oestradiol in comparison to one containing levonorgestrel and ethinylestradiol on markers of endocrine function

“…In particular, 17β-oestradiol (E2) has been investigated as an alternative to synthetic EE. Early attempts to incorporate E2 into COCs were unsuccessful due to poor cycle control, especially when administered as part of a monophasic or biphasic regimen6-9. Despite these early setbacks, it is still hypothesised that the use of E2 in combination with a suitable progestogen would improve the safety of COCs and patient tolerability10.…”

Pharmacokinetics of an oral contraceptive containing oestradiol valerate and dienogest

“…To further improve the tolerability of OCs, and to broaden the choice for OC users, attempts have been made to partially or completely replace ethinyloestradiol (EE) with natural 17b-oestradiol (E 2 ) [11][12][13][14][15][16][17][18][19][20][21][22][23] , which is produced by the human body. The replacement of EE with E 2 , however, resulted in unsatisfactory cycle control when E 2 was administered as part of monophasic or biphasic regimens in clinical trials 11,14,17,[21][22][23][24] .…”