Half a century with hormonal contraception
The first birth control pills appeared back in 1960 in the United States. Despite the pronounced side effects of the first drugs, they were so in demand that after 5 years, millions of women already used tablets.
And now, half a century later, the importance of the hormonal method of contraception is difficult to overestimate. The 200 largest world historians agreed that neither the theory of relativity, nor the nuclear bomb, nor even the Internet (!) Had such an effect on a twentieth-century society as a contraceptive pill.
Today in Russia 24 types of combined oral contraceptives are registered. Let's see how the drugs of hormonal contraception are distinguished.
Combined oral contraceptives (COCs) are so named because the composition of these tablets includes two hormones (or rather, their analogues) - estrogen and gestagen. (There are also mini-drinks containing one hormone, but this is not about them.) Estrogen and gestagen enter the body in different combinations. At that time, when the body does not receive hormones, a woman begins with “withdrawal bleeding” or, simply, menstruation.
There are three generally accepted classifications of COCs: by estrogen component; progestogen; and according to the dosage regimen for one cycle.
Estrogen componentAccording to this principle, all available types of COCs are divided intotwo kinds: ethinyl estradiol-containing and based preparations estradiol valerateThey are also NOC (natural oral contraceptives).
Until recently, it was exclusively used as an estrogen component ethinyl estradiol (EE), a reliable but fairly tough synthetic hormone. Among the EE-containing preparations, the following types are distinguished:
Highly dosed (Non-Ovlon, Anteovin) - contain 50 μg of ethinyl estradiol (EE). They have not been used for a long time due to the high risk of side effects.
Low dose - contain
Microdosed - containing
In 2009, the first and so far the only a drug, containing estradiol valerate as an estrogen component, - “Klayra.” Estradiol Valerate is chemically identical to the hormone secreted by the female body. Its effect is milder than that of EE, hence the name “natural oral contraceptive” arose.
Attempts to create a contraceptive drug based on estradiol valerate have been ongoing for a long time, but the softness of its effect was fraught with possible intermenstrual bleeding. In "Klaire" to solve this problem applied dienogestreliably regulating the growth of the endometrium, anddynamic dosing regimen.
Progestogen componentSo, estrogen is designed to stabilize the menstrual cycle, and gestagen prevents pregnancy. Initially, as a progestogen component were used testosterone derivatives. Along with a high progestagenic effect, they to one degree or another had residual androgenic activity. Thus, COCs containing levonorgestrel and other hormones - desogestrel, gestodene, - which appeared in the 70−80s.
Further evolution of gestagens was aimed at eliminating androgenic activity. As a result, gestagens with antiandrogenic action were also created: cyproterone acetate, dienogest, drospirenone. Drospirenoneamong other things, it prevents the retention of excess fluid in the body, which is observed in some cases against the background of testosterone derivatives in combination with EE.
Dosage regimenFrom what doses and in what combination two hormonal components are used, additional non-contraceptive properties of the drugs depend.
If all the tablets in the package contain the same amount of estrogen and progestogen, the drug is called "Monophasic". Such drugs provide good control of the cycle, with their help it is easy to “postpone” menstruation or switch to prolonged use
At the end
As a result of many years of research, a unique dynamic dosing regimenrepeating the natural female cycle as much as possible. The package contains 26 active tablets with a gradual decrease in the dose of estrogen and an increase in the dose of gestagen and 2 placebo tablets. This regimen contributes to a more stable bleeding profile and good tolerance, while having high contraceptive reliability. In the class of the dynamic dosing regimen, only Klaira is currently represented. Let's hope that her appearance opens a new era - natural and even safer hormonal contraception.
Oksana Bogdashevskaya, obstetrician-gynecologist