Etonogestrel Implant for Birth Control

The etonogestrel implant (synonym: contraceptive rod) is an implanted hormonal contraceptive (contraceptive) that is implanted subcutaneously and is based on the action of etonogestrel, which belongs to the progestins (hormone). The use of the implant is useful for women who wish to use contraception (contraception) for several years. Implantation of the etonogestrel preparation provides safe contraception for up to three years. The Pearl index* of the Etonogestrel implant is given by the manufacturer as 0.1, so that this preparation is currently one of the safest contraceptives. The etonogestrel implant is developed and marketed by MSD SHARP & DOHME GmbH under the name Implanon. * The Pearl index is a measure of how safe and reliable a contraceptive method is. It indicates the number of pregnancies per 100 women who have used the respective method of contraception for one year.

Indications (areas of use)

  • Adult women of childbearing age – the etonogestrel implant is in principle suitable as a contraceptive method (contraceptive) for all women who want to use contraception for several years and have no contraindications (contraindications; see below). The preparation is particularly suitable for women who should not take estrogens, who have contraindications to the IUD (intrauterine device) or who have difficulty inserting an IUD. Breastfeeding mothers can also use the etonogestrel implant, as it has no adverse effects on lactation (breast milk production), according to recent studies.

Contraindications

Relative contraindications

  • Obesity (overweight) – clinical trials did not integrate women who weighed more than 130% of the ideal weight.
  • Diabetes mellitus – the active ingredient of the implant may have effects on glucose tolerance (glucose utilization) in women.
  • Cardiovascular disease – various hormonal contraceptives increase the likelihood of myocardial infarction (heart attack) to a small extent. If you have a history of cardiac disease, you may want to avoid hormonally based contraception.
  • Depression – Etonogestrel increases the likelihood of the onset of depressed mood, so potentially at-risk individuals should refrain from taking it.
  • Hyperlipoproteinemia/hyperlipidemia (dyslipidemia) – taking etonogestrel possibly leads to an increase in triglycerides (neutral fats).
  • Smokers – smoking significantly increases the likelihood of thromboembolism in combination with hormonal contraceptives.
  • Acne – etonogestrel implant may increase acne in women.

Absolute contraindications

  • Hormone-dependent tumors – Women suffering from a hormone-dependent tumor that can be affected by etonogestrel must not use etonogestrel implants.
  • Thrombosis – if a woman has already experienced thrombosis or thromboembolism, the use of etonogestrel implants is contraindicated.

Before therapy

  • Exclusion of drug interactions – Etonogestrel can interact with diverse agents, so a precise drug history is essential before implantation. Potential drug interactions are primarily due to interference with the CYP3A4 enzyme (isoenzyme of the cytochrome P450 family). Medication changes to consider include benzodiazepines, bosentan, carbamazepine, phenytoin, and vitamin K antagonists (coumarins).
  • Exclusion of gravidity (pregnancy) – pregnancy should be excluded before implantation. If pregnancy occurs despite implantation of the preparation, the implant should be removed.
  • Exclusion of contraindications (contraindications) – to reduce adverse drug reactions and complications, before implantation must be checked by means of examination and medical history, whether the woman does not suffer from any diseases that prohibit implantation.
  • Taking the “mini-pill” – before implantation of the rod, it is useful to use a contraceptive method based on the action of the progestogen desogestrel for three months to check whether the hormone is tolerated.

The procedure

The basic principle of the etonogestrel implant is based on the action of the drug etonogestrel, which is absorbed from the implant very slowly and in low concentrations by the body. Etonogestrel represents an active metabolite (degradation product) of desogestrel. Etonogestrel reduces the release of luteinizing hormone (LH) so that ovulation is inhibited (prevented). In addition, the active ingredient affects the cervical mucus (mucus of the cervix), the endometrium (lining of the uterus) and the motility of the tubes (motility of the fallopian tubes). The increased level of progestin reduces the permeability of the cervical mucus to sperm. The combination of mechanisms of action allows for a low failure rate of 0.0449%. Implantation of the rod subcutaneously (under the skin) on the inner side of the upper arm is performed by the physician under local anesthesia (local anesthetic). After three years, the rod is removed. In order to achieve an optimal effect of the implant, it is necessary that the implant is placed in an optimal way. After implantation, the Etonogestrel rod should still be palpable under the skin. This is important for later removal. Notice: Only physicians who have completed insertion and removal training should insert and remove Implanon NXT. Implants that are not palpable should only be removed by a physician experienced in removing deep-seated implants.

After therapy

The correct position should be checked by a physician immediately after insertion and at each follow-up visit. Users should seek immediate medical attention if they are unable to palpate the implant during their own occasional checks. Implantation of the rod provides reliable contraception for three years. After this period, the plastic rod should be removed immediately and a new one inserted. If pregnancy is desired after implantation, the implant can be removed without any problems. After removal of the implant, the monthly ovulatory cycles (cycles with ovulation) resume immediately.

Possible complications

  • Changes in menstruation – a change in the pattern of bleeding due to the use of etonogestrel is likely.
  • Ectopic pregnancy (extrauterine pregnancy) – ectopic pregnancy is the nidation (implantation) of the blastocyst (fertilized egg; stage of embryogenesis characterized by the formation of a blastocoel (fluid-filled cavity); it emerges from the morula, a developmental stage of early embryogenesis) outside the uterus (womb) on approximately day 4 after fertilization. The risk of ectopic pregnancy is greater with the use of a hormonal contraceptive.
  • Thromboembolism – implantation of the etonogestrel rod increases the likelihood of thrombus (blood clot) formation in a venous vessel. The risk can be dramatically increased by additional factors such as smoking.
  • Cephalgia (headache)
  • Acne
  • Amenorrhea (absence of menstruation for more than 3 months).
  • Mastagia (cycle-independent breast pain).
  • Weight gain
  • Depression
  • Back pain
  • Flu-like symptoms
  • Implant migration in vessels, lungs, and chest (1.3 per million radiopaque implants sold with etonogestrel)