Menstrual cycle control

Due to the unique biological similarity of drospirenone (e.g., mild anti-aldosterone and anti-androgenic activity) to the natural progesterone, Yasmin has important advantages over the known oral contraceptives [14]. For example, the use of Yasmin does not initially cause any increase in body weight, and it is also effective in treating mild to moderate acne. Likewise, menstrual cycle control is excellent. 

An appropriate dose of oestrogen + progestogen gives excellent reliability with good menstrual cycle control. The following account applies to these combined preparations. 

Studies have been carried ont on levels of hormones involved in the response to starvation and in control of the menstrual cycle in anorexic patients ... 

Figure 19.13 Relative thickness of the endometrium during the menstrual cycle. Arrows show peak concentrations of hormones involved in control of regeneration of the endometrium.

These correlation studies stimulated experiments to identify the active chemical cues. Russell etal. (1980) rubbed underarm perspiration from a single woman onto the upper lip of five women aged 19-39 years. After 5 months, the odor-exposed women differed from one another in their onset of the menstrual cycle by 3.4 days, on average, compared with 9.2 days in the control group. Before the experiment, the mean differences had been 9.3 and 8.0 days, respectively. The volunteers were aware of the purpose of the experiment. 

Estradiol is the most important of the estrogens. Like progesterone, it is synthesized by the ovaries and, during pregnancy, by the placenta as well. Estradiol controls the menstrual cycle, it promotes proliferation of the uterine mucosa, and is also responsible for the development of the female secondary sexual characteristics (breast, fat distribution, etc.). 

A low dosage of progestin ( mini-pill ) is used, in the form of medroxyprogesterone acetate, which is active at a very low dose. The mini-pill does not inhibit ovulation, but rather interferes with the endometrium and the cervical mucus. The use of this pill prevents most of the side effects of oral contraception, specifically nausea, water retention, and in some cases thrombophlebitis. However, a lower success rate and other frequent side effects have reduced the widespread acceptance of this preparation. Nevertheless, the mini-pill has a role to play in certain specific situations. For example, in an uncommon form of epilepsy called catamenial epilepsy, female patients will experience seizures at particular times during their menstrual cycle, reflecting the fact that seizure focus is stimulated by estrogens but inhibited by progestins. In such women, the mini-pill may afford not only birth control but also improved seizure control. 

Hormonal control of mating behaviour is well documented in animals. In rats, estrogen and, to a lesser extent, progesterone control lordosis behaviour via the central nervous system (CNS). In female non-human primates, attractiveness and proceptivity change during the menstrual cycle or as a result of sex steroid administration. The effects of hormones on receptivity are unclear. It is assumed that steroid hormones influence behaviour in humans as they do in animals however, it is difficult to differentiate the effects of social and other environmental factors from the effects of sex steroids on mating behaviour in humans. 

Knobil E (1980) The neuroendocrine control of the menstrual cycle. Recent Prog Horm Res, 36. 

The effects of in-utero exposure to diethylstilbestrol on the menstrual cycle have been studied prospectively in 198 women and in 162 unexposed controls (44). A major limitation of this study was the exclusion of women with a severe menstrual abnormality. Exposure to diethylstilbestrol was associated with a statistical significantly lower duration of menstrual bleeding but not with dysmenorrhea. For most women exposed to diethylstilbestrol, any effects on reproductive hormonal function are in all probability minor, if present at all. 

In a randomized, placebo-controlled study in women who received leuprolide acetate depot 11.25 mg intramuscularly with tibolone 2.5 mg/day (n = 36), leuprolide acetate depot 11.25 mg with placebo (n = 37), or a placebo injection with placebo tablets (n = 39), irritable bowel syndrome related to the menstrual cycle improved in those who received leuprolide (5). There were hot flushes in those who took leuprolide compared with placebo no data were given about the frequency of hot flushes, but there were no withdrawals because of this symptom. Amenorrhea also occurred. Both flushing and amenorrhea are expected adverse effects of leuprolide. 

Rings containing danazol were designed to control and treat pelvic endometriosis. Danazol acts directly on endometriotic tissue, inhibits DNA synthesis, and induces cell apoptosis. Danazol locally administered did not show inhibition of ovulation on the contrary, oral administration produced a lack of menstrual cycle. Consequently, the main mechanism of action after local administration was reported to be the direct action on endometriotic cells. Danazol probably diffuses through vaginal mucosa and reaches the deep layers, where infiltrating endometriosis takes place. This behavior allows for the avoidance of the side effects, which characterize oral therapy [41]. 

---