Oral contraceptives hormonal adverse effects

Thus, our attention should shift from the concern of potential adverse effects to the health benefits imparted by hormonal contraceptives. The use of oral contraceptives for at least 12 months reduces the risk of developing endometrial cancer by 50%. Furthermore, the risk of epithelial ovarian cancer in users of oral contraceptives is reduced by 40% compared with that on nonusers. This kind of protection is already seen after as little as 3-6 months of use. Oral contraceptives also decrease the incidence of ovarian cysts and fibrocystic breast disease. They reduce menstrual blood loss and thus the incidence of iron-deficiency anemia. A decreased incidence of pelvic inflammatory disease and ectopic pregnancies has been reported as well as an ameliorating effect on the clinical course of endometriosis. 

Oral contraception and hormone replacement therapy are dealt with specifically in separate monographs. Here the general adverse effects of estrogens for any indication are reviewed. 

Hormonal contraception relies on the actions of estrogens and progestogens, of which oral contraceptives contain a mixture. The adverse effects of the separate components are discussed in other monographs. 

Since post-treatment amenorrhea of more than 6 months duration was first suggested as an adverse reaction in around 1965, much work has been devoted to delineating the risk and prognosis of menstrual changes after the withdrawal of hormonal contraception. It is now recognized that post-treatment amenorrhea occurs in 0.7-0.8% of women, but this is no different from the background rate of spontaneous secondary amenorrhea. No cause and effect relation between oral contraceptive use and subsequent amenorrhea has been documented. 

In another study of the LNG-IUS in 200 young nulli-parous women, half of whom received the intrauterine system and the remainder an oral contraceptive for 1 year, 20% of those in the LNG-IUS group withdrew, one-third because of pain the adverse effects in the oral group, in which 28% withdrew, were hormonal (53). 

The manufacturer also points out that combined oral contraceptives (and presumably the combined hormonal contraceptive patch) must not be taken with co-cyprindiol. To do this would be analogous to doubling the ethinylestradiol dose with consequent increased risk of adverse effects. In addition, some of the progestagens in combined oral contraceptives have weak androgenic effects, which could oppose the benefits of cyproterone. 

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