Implanon
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| Implanon
| |
| Background | |
| B.C. type | Hormonal Progestin-only implant |
| First use | 1998 (Indonesia) |
| Failure rates (per year) | |
| Perfect use | 0.038% |
| Typical use | 0.038% |
| Usage | |
| Duration effect | 3 years |
| Reversibility | Yes |
| User reminders | Requires removal after the 3 years |
| Advantages | |
| Benefits | Longterm contraception. |
| Disadvantages | |
| STD protection | No |
| Periods | Initial irregular light spotting |
| Weight gain | Yes |
Implanon, made by Organon International, is a single-rod contraceptive subdermal implant that is inserted under the skin of a woman's upper arm. The 40 mm by 2 mm Implanon rod contains 68 milligrams of the gonane progestin etonogestrel which is released over a three year period.
Peak serum etonogestrel concentrations have been found to reach 781–894 pg/mL in the first few weeks, gradually decreasing to 192–261 pg/mL after 1 year, 154–194 pg/mL after 2 years, and 156–177 pg/mL after 3 years, maintaining ovulation suppression and contraceptive efficacy.[1] Implanon may be removed at any time, but must be removed after three years.
Implanon was first approved for use in Indonesia in 1998, was subsequently approved for use in over 30 other countries, and has been used by over 2.5 million women worldwide. Implanon was approved for use in the United States by the FDA on July 17, 2006.
Contents |
Mechanism of action[edit]
The mechanism of action of progestin-only contraceptives depends on the progestin activity and dose.[2] Intermediate dose progestin-only contraceptives, like Implanon (or the progestin-only pill Cerazette) allow some follicular development but inhibit ovulation in almost all cycles. Like all progestin-only contraceptives, Implanon also has a progestogenic effect of increasing cervical mucus viscosity, thereby inhibiting sperm penetration. In anovulatory cycles using progestin-only contraceptives, the endometrium is thin and atrophic. If the endometrium was also thin and atrophic during an ovulatory cycle, this could theoretically interfere with implantation of a blastocyst (embryo).
Insertion[edit]
Local anaesthetic is applied to the upper arm, and then a needle-like applicator is used to insert the implanon rod under the skin. The procedure can take less than a minute. An experienced clinician is required for proper insertion, to minimize the risk of nerve damage,[3] or misplacement which could result in unintended pregnancy. Implant site complications are experienced by 3.6 percent of patients, and include swelling, redness, hematoma and pain.
Side effects and risks[edit]
There are notable side effects caused by Implanon that occur in some women. Irregular periods, headaches, acne, weight gain and abdominal pain were among the most commonly reported side effects in clinical trials.
Eleven percent of women had Implanon removed because of irregular menstrual bleeding. Some women may have no menstrual period at all while using Implanon.[4]
It is not known whether Implanon changes a woman's risk for breast cancer.[1][5]
Complications[edit]
Complications which can occur include:
- impalpability of implant
- broken or damaged implant
- slight migration
- fibrosis.
If Implanon is "impalpable"—cannot be felt—an ultrasound must be performed. Surgery under local or general anesthesia may be required to remove an impalpable Implanon implant, especially if it is broken, damaged, has migrated, or is deeply embedded in scar tissue or fibrosis.
In rare cases, the increase in hormone levels resulting from Implanon has been linked to various forms of mental illness including depression, mood disorders and psychosis. This is likely to be the result of deep insertion into the muscle, and associated damage to the implant. Users experiencing a sudden change in mood, personality or motivation should consult their doctor immediately.[citation needed]
References[edit]
- ↑ 1.0 1.1 Implanon label (PDF). FDA (2006-07-17). Retrieved on 2006-08-23.
- ↑ Glasier, Anna (2006). “Contraception”, DeGroot, Leslie J.; Jameson, J. Larry (eds.): Endocrinology, 5th edition, Philadelphia: Elsevier Saunders, pp. 3000-1. ISBN 0-7216-0376-9.
- ↑ Wechselberger G, Wolfram D, Pulzl P, Soelder E, Schoeller T (July 2006). "Nerve injury caused by removal of an implantable hormonal contraceptive". Am J Obstet Gynecol 195 (1): 323-6. PMID 16813761.
- ↑ Susan Heavey & Lisa Richwine. "New implantable contraceptive for women gets go-ahead", Reuters, Jul 18, 2006.
- ↑ Implanon patient information (PDF). Organon USA Inc. (July 2006). Retrieved on 2006-08-23.
External links[edit]
| Birth control edit | ||
|---|---|---|
| Sterilization: | Tubal ligation, Vasectomy, Essure | |
| Post-intercourse: | Emergency contraception • Abortion: Surgical, Medical, Herbal/Drug | |
| Intra-uterine: | IUD, IUS (progesterone) | |
| Anti-estrogen: | Ormeloxifene (a.k.a. Centchroman) | |
| Hormonal: | Combined: COCP ('the Pill'), Patch, Nuvaring
Progestogen only: POP mini-pill, Depo Provera, Norplant, Implanon | |
| Barrier: | Condom, Diaphragm, Shield, Cap, Sponge, Spermicide | |
| Behavioral: | Coitus interruptus, Fertility awareness, Rhythm Method, Lactational
Avoiding vaginal intercourse: Anal sex, Oral sex, Outercourse, Masturbation, Abstinence | |
