And now, half a century later, the importance of the hormonal method can hardly be overestimated. 200 of the world’s largest historians agreed that neither the theory of relativity, nor the nuclear bomb, nor even the Internet had such an impact on the society of the twentieth century as the contraceptive pill.
Today, 24 types of combined oral contraceptives are registered in Russia. Let’s see how all these drugs are distinguished.
Combined oral contraceptives (COCs) are so called because these pills contain two hormones (or rather, their analogs) – estrogen and gestagen. (There are also mini-pills containing one hormone, but we are not talking about them now.) Estrogen and gestagen enter the body in different combinations. During the period when the body does not receive hormones, the woman begins “withdrawal bleeding”, or, in a simple way, menstruation.
There are three generally accepted classifications of COCs: according to the estrogenic component, according to the gestagenic component and according to the dosage regimen during one cycle.
Estrogenic component
According to this principle, all available types of COCs are divided into two types: ethinyl estradiol-containing and preparations based on estradiol valerate, they are also NOC (natural oral contraceptives).
Until recently, it was used exclusively as an estrogenic component ethinyl estradiol (EE), a reliable, but tough enough synthetic hormone. Among the EE-containing preparations, the following types are distinguished:
High dose (“Non-ovlon”, “Anteovin”) – contain 50 mcg of ethinylestradiol (EE). They have not been used for a long time due to the high risk of side effects.
Low-dose – contain 30–35 mcg EE. There are many such drugs, these are Yarina, Zhanin, Marvelon, Diane-35, etc. A feature of low-dose drugs is good cycle control with high contraceptive reliability.
Microdosed – containing 15–20 μg EE. These are well-known to us “Jess”, “Logest”, “Mersilon”. Despite the low content of hormones, micro-dosage preparations are quite reliable. During the adaptation period, spotting spotting is possible, but contraceptive protection works regardless of the presence of secretions.
In 2009, the first was developed and so far the only drug containing estradiol valerate as an estrogenic component – “Klayra”… Estradiol valerate is chemically identical to a hormone produced by the female body. Its effect is milder than that of EE, hence the name “natural oral contraceptive”.
Attempts to create a contraceptive drug based on estradiol valerate have been carried out for a long time, but the mildness of its effect was fraught with possible intermenstrual bleeding. In “Klayr” to solve this problem, dienogest, reliably regulating the proliferation of the endometrium, and dynamic dosing regimen.
Progestational component
So, estrogen is designed to stabilize the menstrual cycle, and gestagen prevents pregnancy. Originally used as a gestagenic component testosterone derivatives… Along with a high progestogenic effect, they, to one degree or another, had residual androgenic activity. This is how COCs were created containing levonorgestrel and other hormones – desogestrel, gestodene, which appeared in the 70s and 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. Drospirenone among 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.
Dosing regimen
The additional non-contraceptive properties of the drugs depend on the doses and in what combination the two hormonal components are used.
If all tablets in the package contain the same amount of estrogen and gestagens, the drug is called single-phase… Such drugs provide good control of the cycle, with their help it is easy to postpone menstruation or switch to prolonged administration (4-5 menstruation per year).
In the 70s was created biphasic the drug “Anteovin”. It is no longer used.
In the late 70s, a new dosage regimen was created – three-phase… Now three different dosages create a semblance of natural hormonal fluctuations. The drug “Trikvilar” is very popular today.
As a result of many years of research, a unique dynamic dosing regimenthat repeats 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 Klayra is currently represented. Hopefully, it will usher in a new era of natural and safer contraception.
Author: obstetrician-gynecologist