Etonogestrel implant is a hormone-releasing device containing etonogestrel which is used to prevent unwanted pregnancy. It is one of the most effective birth control methods with a failure rate of 0.05% per year.
Indications for use
Etonogestrel implant is used as a long-term contraceptive.
The device is suitable for women who:
- do not plan a pregnancy in the next few years;
- have a high risk of unwanted pregnancy;
- cannot take estrogens (if there are contraindications);
- are in the postpartum period (including breastfeeding);
- have a negative experience of taking COCs (tablets);
- are looking for a reversible alternative to sterilization.
Mechanism of action
Etonogestrel contraceptive implant is a rod placed in the needle of a sterile disposable applicator. The system contains the active substance etonogestrel (68 mg).
The drug injected subcutaneously defies biological decay. Contraceptive properties of the drug are due to suppression of ovulation – usually, ovulation is not observed during the first two years and only in the 3rd year were rare cases of a weakening of the contraceptive effect. In this case, the function of the ovaries is suppressed only partially.
Also, the implant changes the viscosity of the cervical secret, which blocks the passage of spermatozoa.
The contraceptive effect of etonogestrel is reversible, menstruation is restored after the removal of the implant.
The drug also does not change the mineral plane of bone tissue and the action of lipids.
After the insertion of the drug under the skin, the active substance is rapidly absorbed into the blood, but eventually, the release of etonogestrel is reduced, which leads to a decrease in its concentration in the first months of use. By the end of year 1, the concentration of the substance in blood plasma is about 200 ml, and by the 3rd it is reduced to 156 ml. The concentration of active substance in the blood may vary depending on the body weight of the woman.
Etonogestrel and its derivatives are excreted mostly by the kidneys and by the intestine.
How to use Etonogestrel implant?
Etonogestrel is administered subcutaneously in the form of an implant. This procedure should be performed by a doctor who has received appropriate training.
Before the introduction of the drug, pregnancy should be excluded and a doctor should carefully read the woman’s medical history and conduct a survey. The frequency and nature of further medical examinations must be established for each woman individually, but certainly three months after the administration of the system and at least 1 time in six months in the future.
Etonogestrel contraceptive implant does not protect against diseases that are sexually transmitted.
If a woman before did not take any contraceptives, the drug can be introduced in the first 5 days of the menstrual period.
When switching from one contraceptive to Etonogestrel implant system, it is necessary to install the device the next day after the usual intake of the previous drug or on the day of removal of the vaginal ring / transdermal patch. If a woman took progestin-only contraceptives before, the system can be inserted on any day when the next injection is expected.
After an abortion in the first trimester of pregnancy, the implant can be injected immediately. After an abortion in the second trimester or after childbirth, the drug is administered on the 21-28th day. Before implantation, it is necessary to exclude pregnancy, and if a woman had sexual intercourse shortly before installing the device, she needs to wait for menstruation.
The implant is inserted under the skin with a special applicator under sterile conditions and only by a specialized doctor.
Do not inject the implant too deep, as it may damage the nerve or migrate the stem if it is inserted into the muscle or fascia. When the drug enters the vessel, implant palpation becomes impossible, which creates difficulties in its subsequent removal.
If the implant was successfully inserted, you can feel it at the installation site.
Removal of Etonogestrel birth control implant should be performed by the doctor who installed it.
If you cannot feel a rod, it is necessary to make an MRI or ultrasound before removing the device. If there is any doubt about the presence of the birth control implant, it is necessary to make a blood analysis – the concentration in the plasma of etonogestrel indicates the presence of the drug.
Surgical search for a rod without first determining its location is strictly contraindicated.
Before removing the contraceptive it is necessary to treat the place of its location with an alcohol solution or another disinfectant, and then conduct anesthesia at the excision site.
The maximum validity of Etonogestrel implant is 3 years. If the woman wants to continue using this drug, its installation can be carried out immediately after removal of the previous implant in the same place.
Use of Etonogestrel birth control implant is contraindicated in the following cases:
- mammary cancer;
- thromboembolism and venous thrombosis;
- severe liver disease;
- vaginal bleeding of unknown origin;
- hypersensitivity to the components of the drug.
With extreme caution, the drug should be prescribed to patients suffering from diabetes mellitus, liver cancer, prolonged immobilization after surgery, and during a breastfeeding period.
Possible side effects caused by Etonogestrel implant system include:
- mammary cancer;
- VTE, pulmonary embolism, deep vein thrombosis;
- itching or jaundice, as a consequence of cholestasis;
- systemic lupus erythematosus;
- stones in the bile;
- hemolytic-uremic syndrome;
- herpes gestationis in the anamnesis;
- loss of hearing as a consequence of osteosclerosis.
Etonogestrel birth control implant should not be combined with other contraceptive medications, as this may reduce the protective effect of the drug or cause a breakthrough bleeding.
Interaction can occur with drugs that induce microsomal enzymes of the liver, in particular elements of cytochrome P450, which leads to an increase in the clearance of sex hormones – barbiturates, carbamazepine, phenytoin, ritonavir, felbamate and drugs containing St. John’s Wort. Patients who take such drugs should use additional contraceptives for some time. Women who require long-term treatment with drugs that induce hepatic enzymes need to discontinue using the contraceptive implant and use other methods of contraception.
Pregnancy and breastfeeding
Etonogestrel implant system is contraindicated in pregnancy, so if a woman becomes pregnant while using the device, it must be removed. High doses of progestogenic compounds can affect masculinization of female fetuses.
The drug does not affect the structure of breast milk, but a small amount of etonogestrel can be excreted through the woman’s mammary glands. Over time, the concentration of active ingredient in milk decreases. The use of the contraceptive implant during breastfeeding is possible, but only under the supervision of a doctor.
If you plan a pregnancy, the implant can always be removed. The ability to conceive is restored immediately: within the next month.
- This is a contraceptive of reversible action, the hormonal background is restored within 100 hours after removal of the implant, the restoration of ovulation occurs within 3 months;
- The effectiveness of etonogestrel does not depend on the correct application, it provides the most reliable protection against unplanned pregnancy among all methods of contraception;
- A woman can contact a gynecologist to remove the implant system at any time;
- The drug does not change bone mineral density and lipid metabolism;
- The contraceptive provides a highly effective birth control immediately after birth for 3 years;
- When using the device, as well as other contraceptives containing progestogen, the character of menstrual flow may change;
- Contraceptive hormonal drugs can affect some laboratory indicators, including biochemical parameters of the thyroid gland, liver, kidney, adrenal gland, lipid / lipoprotein fraction, corticosteroid-binding globulin, blood clotting, fibrinolysis of carbohydrate metabolism. If you notice any adverse reactions related to the nervous system, it is necessary to refrain from driving transport and performing other activities that require increased attention and speed of psychomotor reactions.