Mechanism of action of oral contraceptives

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Birth control pills are medicines that are taken by mouth to prevent pregnancy from happening. This is one of the most effective and convenient hormonal birth control methods. Understanding the mechanism of action as well as the side effects of birth control pills will help us have a certain basis to choose the right drug for us.

1. Types of birth control pills

Contraceptives have 2 types:
Combined oral contraceptives: Are drugs containing the synthetic form of 2 hormones estrogen and progestin; Progestin-only birth control pills: Pills that contain only the hormone progestin and no estrogen, are also known as minipills. This medication may be useful in cases where women cannot use estrogen for health or other reasons. Not all drugs are suitable for a woman's health condition, so you should consult a doctor. A number of factors may influence the choice of birth control pill, including:
Menstrual status; Are you in the category of breastfeeding? Cardiovascular health; Other possible chronic diseases; Other medications you are taking. Birth control pills, when used as directed, can be more than 90% effective at preventing pregnancy. However, it does not protect a woman from sexually transmitted diseases, including HIV.

2. Mechanism of action of oral contraceptives

Pregnancy is defined as when a woman's egg (released from an ovary) is fertilized by a man's sperm. Once fertilized, the egg will nest inside the uterus, where it will receive enough nutrients to develop into a baby. Hormones in a woman's body prevent further ovulation from occurring and prepare the body to accept the fertilized egg.
Based on this mechanism of pregnancy, oral contraceptives work as follows:
Combined oral contraceptives Combined oral contraceptives work in 2 ways. First, it prevents ovulation, which means that the ovaries can no longer release eggs every month. Besides, it also thickens cervical mucus, which helps sperm to travel more easily to the uterus and fertilize an egg. Thickening of the mucus will prevent sperm from entering the uterus.

Progestin-only birth control pills This also works in different ways, but mainly by thickening the uterine lining so that sperm cannot reach an egg; thins the lining of the uterus so that even if a fertilized egg is fertilized, it is less likely to implant in the uterus After 3 hours, another method of birth control must be used. Therefore, if you cannot be sure that you will always take your pills on time, you should not use this method. Birth control pills contain only progestin and do not contain estrogen, so it can be used by nursing mothers. The drug does not affect the amount of milk secreted as well as the quality of milk.

3. How effective are birth control pills?

If used correctly, birth control pills can work very well. Both the combination pill and the progestin-only pill have a failure rate of 9% when used in practice. That means for every 100 women using the pill, nine will become pregnant.
To be most effective at preventing pregnancy, progestin-only pills must be taken at the same time and within a maximum of 3 hours each day. Combination pills are more flexible, the time of taking can be separated by up to 12 hours a day and still have the effect of protecting the body from pregnancy.
It should be noted that some of the following drugs can reduce the contraceptive effect of birth control pills:
Rifampin (an antibiotic); some HIV medicines such as lopinavir and saquinavir; Some antiepileptic drugs such as carbamazepine and topiramate. Also, birth control pills are less effective if taken when you have diarrhea or vomiting.

4. Benefits of birth control pills

Birth control pills have the following benefits:
Prevent pregnancy 24/7, helping you no longer have to worry about unwanted pregnancy during intercourse; More effective at preventing pregnancy than most other methods of contraception; Helps regulate menstruation: Especially useful for women with irregular or heavy menstrual periods; Easy return to normal: If you stop taking the pill, your period will return to normal and you can get pregnant soon after. Combined oral contraceptives can be effective against the following pathological phenomena:
Acne; Ectopic pregnancy ; Osteoporosis; Fibroids of the breast; Endometrial cancer ; Anemia; Cramps during menstruation. Progestin-only birth control pills, in addition to effective birth control, are safer for women who have the following characteristics:
Inability to take estrogen therapy; Smokers; Persons over 35 years old; People with a history of blood clots; Breastfeeding person.

5. Disadvantages of birth control pills

Birth control pills cannot protect a woman from sexually transmitted diseases if she doesn't use an extra condom.
In addition, another disadvantage of oral contraceptives is that the user must remember to take the pill at the same time every day, there is always a new pack available to replace as soon as the old pack is exhausted to make sure not to miss any. any pill. If this happens, the risk of pregnancy increases.
Besides, some side effects of oral contraceptives have also been recorded in women such as:
Decreased sex drive; Nausea; Abnormal bleeding; Breast pain. These symptoms may disappear after a few months of using oral contraceptives. But if they don't go away, you need to contact your doctor for an examination and advice on whether to switch to another medication.
Another more serious risk when using oral contraceptives - especially the combination pill - is an increased risk of blood clots, leading to:
Formation of deep vein thrombosis; Heart attack; Stroke; Pulmonary embolism . Overall, however, the risk of blood clots forming with any type of birth control pill is pretty low. According to the American College of Obstetricians and Gynecologists, up to 10 out of 10,000 women will develop a blood clot after taking the combined oral contraceptive pill for 1 year. This risk is still lower than the risk of blood clots forming during pregnancy and shortly after delivery.
Knowledge of the mechanism of action of oral contraceptives as well as its side effects and risks will be the basis for women to consider before deciding whether to use them or not, if so, should use them any. To ensure effective contraception while still being safe for your health, you should see your doctor for the most complete advice.

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Reference source: webmd.com; healthline.com