Implanon
Encyclopedia
Implanon, made by Organon International
, is a single-rod long acting reversible
hormonal contraceptive
subdermal implant that is inserted just under the skin of a woman's upper arm. The 4 cm by 2 mm Implanon rod contains 68 milligrams of etonogestrel
(a progestin
) which is released over a three year period. Because of cases of incorrect insertion by medical personnel in the UK, Implanon will be replaced by Nexplanon, which has a pre-loaded applicator for easier insertion.
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. Implanon may be removed at any time, but must be removed after at most 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 Food and Drug Administration (FDA) on July 17, 2006. This is the only contraceptive implant approved by the FDA and sold in the United States.
Hormonal contraceptives also have effects on the endometrium that theoretically could affect implantation, however no scientific evidence indicates that prevention of implantation actually results from their use.
and pain.
in terms of effectiveness in preventing pregnancy, Implanon is one of the most effective forms of birth control
currently available, along with Jadelle.
The failure rate for Implanon is about 0.0449%, as observed in the UK, where only 584 women have reported unwanted pregnancies, out of 1.3 million who have used Implanon since 1999. Unlike other birth control methods, there is no differential for perfect use versus typical use, as no user action is required after insertion. Most cases of failure are due to incorrect insertion or insertion during pregnancy.
If a woman receives an Implant outside the first five days of her period, she should wait to have sex or use a back up method of contraception (such as a condom, female condom, diaphragm, sponge, or emergency contraception) for the following week after implantation to prevent fertilization of an egg. However, if the Implant is inserted during the first five days of a woman's period, she is protected against pregnancy from that very moment.
In comparison, surgical sterilization has a failure rate of 0.2%. While these statistics suggest that Implanon is four times more effective in preventing pregnancy than surgical sterilization, it is important to remember that sterilization is permanent, whereas Implanon must be replaced every three years to continue to be effective. On the other hand, Implanon is completely reversible, while sterilization is permanent and cannot be reversed.
s caused by Implanon are similar to other hormonal birth control methods such as combined oral contraceptive pills, the Ring (Nuvaring
), Depo-Provera, etc.
According to the manufacturer, irregular periods
or prolonged bleeding, headache
s, acne
, weight gain and abdominal pain were among the most commonly reported side effects in clinical trials. 10% of women had Implanon removed because of irregular menstrual bleeding, which can include excessive menstrual bleeding. 20% of women may have no menstrual period at all while using Implanon. The manufacturer advises "Expect your menstrual periods to be irregular and unpredictable throughout the time you are using IMPLANON™". It is not known whether Implanon changes a woman's risk for breast cancer. As with other hormonal contraceptives, women who are older than 35 or who smoke are at higher risk of serious cardiovascular side effects.
In a 2-year study of 330 sexually active American women, 13% discontinued Implanon because of bleeding pattern changes. Other adverse experiences included emotional lability (6.1%), weight increase (3.3%), depression (2.4%) and acne (1.5%).
Implanon has also been shown to induce mild insulin resistance
though the effects are not clinically relevant for healthy women.
An implant that cannot be found through palpation
may be caused by damage, migration or fibrosis
, requiring an ultrasound
assessment or removal.
Organon International
Organon is a human pharmaceutical company headquartered in Oss, Netherlands. In November 2007 the company became a part of Schering-Plough Corporation, acquired Organon, active pharmaceutical ingredient producer Diosynth , and its veterinary pharmaceutical sister company Intervet from Akzo Nobel. ...
, is a single-rod long acting reversible
Long Acting Reversible Contraceptive
Long-acting reversible contraceptive methods are birth control methods that provide effective contraception for an extended period of time without requiring user action.-LARC methods:Available LARC methods include:* Intrauterine device...
hormonal contraceptive
Hormonal contraception
Hormonal contraception refers to birth control methods that act on the endocrine system. Almost all methods are composed of steroid hormones, although in India one selective estrogen receptor modulator is marketed as a contraceptive. The original hormonal method—the combined oral contraceptive...
subdermal implant that is inserted just under the skin of a woman's upper arm. The 4 cm by 2 mm Implanon rod contains 68 milligrams of etonogestrel
Etonogestrel
Etonogestrel is a progestin used in hormonal contraceptives, most notably the subdermal implant Implanon and the contraceptive vaginal ring NuvaRing....
(a progestin
Progestin
A progestin is a synthetic progestogen that has progestinic effects similar to progesterone. The two most common uses of progestins are for hormonal contraception , and to prevent endometrial hyperplasia from unopposed estrogen in hormone replacement therapy...
) which is released over a three year period. Because of cases of incorrect insertion by medical personnel in the UK, Implanon will be replaced by Nexplanon, which has a pre-loaded applicator for easier insertion.
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. Implanon may be removed at any time, but must be removed after at most three years.
Implanon was first approved for use in Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
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
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
by the Food and Drug Administration (FDA) on July 17, 2006. This is the only contraceptive implant approved by the FDA and sold in the United States.
Mechanism of action
The mechanism of action of progestin only contraceptives depends on the progestin activity and dose. Intermediate dose progestin-only contraceptives, like Implanon (and the progestin-only pill Cerazette) allow some follicular development but inhibit ovulation in almost all cycles as the primary mechanism of action. Ovulation was not observed in studies of Implanon in the first two years of use and only rarely in the third year with no pregnancies. A secondary mechanism of action is the progestogenic increase in cervical mucus viscosity which inhibits sperm penetration.Hormonal contraceptives also have effects on the endometrium that theoretically could affect implantation, however no scientific evidence indicates that prevention of implantation actually results from their use.
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, or misplacement which could result in unintended pregnancy. Implant site complications are experienced by 3.6% of patients, and include swelling, redness, hematomaHematoma
A hematoma, or haematoma, is a localized collection of blood outside the blood vessels, usually in liquid form within the tissue. This distinguishes it from an ecchymosis, which is the spread of blood under the skin in a thin layer, commonly called a bruise...
and pain.
Effectiveness in preventing pregnancy
In a comparison of birth control methodsComparison of birth control methods
Different types of birth control methods have large differences in effectiveness, actions required of users, and side effects.-Ease of use:Different methods require different actions of users. Barrier methods, spermicides, and coitus interruptus must be used at every act of intercourse. The male...
in terms of effectiveness in preventing pregnancy, Implanon is one of the most effective forms of birth control
Birth control
Birth control is an umbrella term for several techniques and methods used to prevent fertilization or to interrupt pregnancy at various stages. Birth control techniques and methods include contraception , contragestion and abortion...
currently available, along with Jadelle.
The failure rate for Implanon is about 0.0449%, as observed in the UK, where only 584 women have reported unwanted pregnancies, out of 1.3 million who have used Implanon since 1999. Unlike other birth control methods, there is no differential for perfect use versus typical use, as no user action is required after insertion. Most cases of failure are due to incorrect insertion or insertion during pregnancy.
If a woman receives an Implant outside the first five days of her period, she should wait to have sex or use a back up method of contraception (such as a condom, female condom, diaphragm, sponge, or emergency contraception) for the following week after implantation to prevent fertilization of an egg. However, if the Implant is inserted during the first five days of a woman's period, she is protected against pregnancy from that very moment.
In comparison, surgical sterilization has a failure rate of 0.2%. While these statistics suggest that Implanon is four times more effective in preventing pregnancy than surgical sterilization, it is important to remember that sterilization is permanent, whereas Implanon must be replaced every three years to continue to be effective. On the other hand, Implanon is completely reversible, while sterilization is permanent and cannot be reversed.
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 (corrected for aging etc.).Side effects and risks
Side effectAdverse effect
In medicine, an adverse effect is a harmful and undesired effect resulting from a medication or other intervention such as surgery.An adverse effect may be termed a "side effect", when judged to be secondary to a main or therapeutic effect. If it results from an unsuitable or incorrect dosage or...
s caused by Implanon are similar to other hormonal birth control methods such as combined oral contraceptive pills, the Ring (Nuvaring
NuvaRing
NuvaRing is the trade name for a combined hormonal contraceptive vaginal ring manufactured by Merck that is available by prescription...
), Depo-Provera, etc.
According to the manufacturer, irregular periods
Menstrual cycle
The menstrual cycle is the scientific term for the physiological changes that can occur in fertile women for the purpose of sexual reproduction. This article focuses on the human menstrual cycle....
or prolonged bleeding, headache
Headache
A headache or cephalalgia is pain anywhere in the region of the head or neck. It can be a symptom of a number of different conditions of the head and neck. The brain tissue itself is not sensitive to pain because it lacks pain receptors. Rather, the pain is caused by disturbance of the...
s, acne
Acne vulgaris
Acne vulgaris is a common human skin disease, characterized by areas of skin with seborrhea , comedones , papules , pustules , Nodules and possibly scarring...
, weight gain and abdominal pain were among the most commonly reported side effects in clinical trials. 10% of women had Implanon removed because of irregular menstrual bleeding, which can include excessive menstrual bleeding. 20% of women may have no menstrual period at all while using Implanon. The manufacturer advises "Expect your menstrual periods to be irregular and unpredictable throughout the time you are using IMPLANON™". It is not known whether Implanon changes a woman's risk for breast cancer. As with other hormonal contraceptives, women who are older than 35 or who smoke are at higher risk of serious cardiovascular side effects.
In a 2-year study of 330 sexually active American women, 13% discontinued Implanon because of bleeding pattern changes. Other adverse experiences included emotional lability (6.1%), weight increase (3.3%), depression (2.4%) and acne (1.5%).
Implanon has also been shown to induce mild insulin resistance
Insulin resistance
Insulin resistance is a physiological condition where the natural hormone insulin becomes less effective at lowering blood sugars. The resulting increase in blood glucose may raise levels outside the normal range and cause adverse health effects, depending on dietary conditions. Certain cell types...
though the effects are not clinically relevant for healthy women.
Complications
Complications which can occur include:- impalpability of implant
- broken or damaged implant
- slight migration
- fibrosis
An implant that cannot be found through palpation
Palpation
Palpation is used as part of a physical examination in which an object is felt to determine its size, shape, firmness, or location...
may be caused by damage, migration or fibrosis
Fibrosis
Fibrosis is the formation of excess fibrous connective tissue in an organ or tissue in a reparative or reactive process. This is as opposed to formation of fibrous tissue as a normal constituent of an organ or tissue...
, requiring an ultrasound
Ultrasound
Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Ultrasound is thus not separated from "normal" sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is...
assessment or removal.