Implanon
From Wikipedia, the free encyclopedia
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Implanon
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| 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 | |
| Periods | Minimises pain. 20% of women will stop having their period. |
| Benefits | Longterm contraception. |
| Disadvantages | |
| STD protection | No |
| Periods | Various. |
Implanon, made by Organon International, is a single-rod contraceptive subdermal implant that is inserted just 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. There is no more reliable contraceptive than Implanon.[citation needed]
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.
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[edit] Mechanism of action
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. Finally, Implanon reduces the thickness of the endometrium lining of the uterus, which renders it more difficult for fertilized eggs, zygotes, and blastocysts (early embryos) to implant to the uterus wall, as may the buildups of mucus that Implanon causes. Since these effects of Implanon occur after fertilization, many consider them to be abortive.
[edit] Insertion
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.
[edit] Side effects and risks
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]
Failure rate for Implanon was reported at 0.1%. Most cases of failure were due to incorrect insertion or insertion during pregnancy. In comparison, surgical sterilization has a failure rate of 0.2%.[6]Implanon effectiveness.</ref>
Undesireable effects that may occur include acne, headache, weight gain, breast tenderness, hair loss, mood changes, changes in libido, and abdominial pain. Vaginal bleeding may occur at irregular intervals during the use of Implanon. Some patients do not experience any bleeding at all. It is important to have regular medical check ups, because while irregular bleeding is a common side effect of Implanon, it may rarely be caused by other medical conditions.
[edit] Fertility after Implanon
Within a few days of having Implanon removed the hormones released by Implanon will have left the body. The chances of becoming pregnant should be the same as they were before using Implanon.
[edit] Complications
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]
[edit] References
- ^ a b Implanon label (PDF). FDA (2006-07-17). Retrieved on August 23, 2006.
- ^ Glasier, Anna (2006). "Contraception", in 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 August 23, 2006.
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[edit] External links
| Birth control edit | ||
|---|---|---|
| Sterilization: | Tubal ligation, Vasectomy, Essure | |
| Post-intercourse: | Abortion: Surgical, Medical Emergency contraception |
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| Intra-uterine: | IUD, IUS (progestogen) | |
| Anti-estrogen: | Ormeloxifene (a.k.a. Centchroman) | |
| Hormonal: | Combined: COCP ('the Pill'), Patch, Nuvaring Progestogen only: POP mini-pill, Depo Provera, Norplant, Implanon |
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| Barrier: | Male condom, Female condom, Diaphragm, Shield, Cap, Sponge, Spermicide | |
| Behavioral: | Coitus interruptus, Rhythm Method, Lactational, Fertility awareness Avoiding vaginal intercourse: Anal sex, Oral sex, Outercourse, Masturbation, Abstinence |
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