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 1 Mechanism of action 2 Insertion 3 Side effects and risks 4 Complications 5 References 6 External links

[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. 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).

[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, increased blood pressure, increased blood clots, abdominal pain and frequent vaginal bleeding are among the short-term side effects. Long-term effects are unknown.

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]

[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.

[edit] References

1. ^ ^{a b} Implanon label (PDF). FDA (2006-07-17). Retrieved on 2006-08-23.
2. ^ Glasier, Anna (2006). “Contraception”, DeGroot, Leslie J.; Jameson, J. Larry (eds.): Endocrinology, 5th edition, Philadelphia: Elsevier Saunders, pp. 3000-1. ISBN 0721603769.
3. ^ 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.
4. ^ Susan Heavey & Lisa Richwine. "New implantable contraceptive for women gets go-ahead", Reuters, Jul 18, 2006.
5. ^ Implanon patient information (PDF). Organon USA Inc. (July 2006). Retrieved on 2006-08-23.

[edit] External links

• Official website