Bulletin: Single-rod contraceptive implant Implanon gets Food & Drug Administration's OK

Women who are interested in long-term, reliable birth control now have a new option: The Food and Drug Administration (FDA) has just approved Implanon, the single-rod subdermal contraceptive implant.

Marketed by Organon of Roseland, NJ, and Oss, the Netherlands, Implanon continually releases a low, steady dose of the progestin etonogestrel for up to three years. The device, which is about the size of a matchstick, is made of a soft medical polymer. It is inserted subdermally just beneath the skin on the inner side of a woman's upper arm during an in-office procedure.

The July 2006 regulatory approval ends an almost two-year wait since the agency's November 2004 issuance of "approvable status" to the device. The device is available in more than 30 countries, including the United Kingdom, Chile, Egypt, Finland, and the Slovak Republic.1

The availability of a highly effective long-acting, single-rod contraceptive implant represents good news for patients, notes Andrew Kaunitz, MD, professor and assistant chairman of the Department of Obstetrics and Gynecology at the University of Florida Health Science Center in Jacksonville.

Anita Nelson, MD, professor in the Obstetrics and Gynecology Department at the University of California in Los Angeles (UCLA) and medical director of the women's health care programs at Harbor-UCLA Medical Center in Torrance, says, "I am excited that U.S. women will have access to this extremely effective, convenient method of birth control. The low hormone levels, the unambiguous contraceptive mechanism of action, and the ease of insertion and removal are all important features for the patient and the provider."

Will Implanon be offered in your clinic? Before you can prescribe the method, you must first undergo training in inserting and removing the device. At CTU press time, the first wave of Organon-sponsored provider training was set to begin in August 2006. Providers who are interested in the three-hour training can sign up by enrolling on the provider section of the product web site, www.IMPLANON-USA.com, or by calling a toll-free telephone number, (877) IMPLANON [(877) 467-5266], says Frances DeSena, company spokes-woman. The telephone line will be manned from 8 a.m. to 8 p.m. Eastern Time to accommodate all time zones. The company plans to offer training in various geographic areas to allow providers to choose a convenient site, she notes.

Beginning in October, 85 Planned Parenthood affiliates will be trained in insertion and removal of the hormonal implant through an Organon-sponsored training program. Subsequent training sessions will be held for the remaining affiliates in the winter, according to the New York City-based Planned Parenthood Federation of America.

Nelson says, "I think the careful, slow introduction of this product, with it being sold only to clinicians after they have been trained and with the regional network of providers to back up their colleagues should problems arise, will help ensure the long-term success of this implant."

Pricing for the device has not been set, says DeSena; however, it will be competitive in cost in comparison with other forms of hormonal contraception, she notes. The company already is meeting with managed care organizations to see that Implanon is added to formularies, says DeSena. According to the Implanon hotline, the product will be widely available in the fourth quarter of 2006.

Implanon is safe, highly effective, and rapidly reversible, according to research.1 No pregnancies were recorded in a study of 330 women with normal menstrual cycles who used the implant for up to two years.2 The most common bleeding pattern observed throughout the study was infrequent bleeding, defined as less than three episodes of bleeding in a reference period (excluding amenorrhea). Infrequent, prolonged, and frequent bleeding patterns were most common early in the study and declined thereafter.2

Forty-three women (13%) withdrew from the study because of bleeding pattern changes, and 76 women (23%) discontinued because of other adverse experiences, such as emotional lability (6.1%), weight increase (3.3%), depression (2.4%), and acne (1.5%). The return to normal menstrual cycles and fertility was rapid after removal.2

Implanon does not affect bone mineral density. In a separate study, researchers detected no decrease in levels during three years of single-rod implant use.3

Which women may be potential candidates for the contraceptive implant? According to A Pocket Guide to Managing Contraception, Implanon is particularly good for women with contraindications to or side effects from estrogen, such as:

  • recently postpartum women;
  • mothers who are exclusively breast-feeding;
  • smokers older than age 35;
  • women who had or fear chloasma, worsening migraine headaches, hypertriglyceridemia, or other estrogen-related side effects.4

Among Implanon's contraindications are suspected pregnancy and active venous thromboembolic disorder.1

Women who receive Implanon should be counseled to check that the implant is in place following insertion. If the device is not placed properly, it may not prevent pregnancy or it may be difficult or impossible to remove. To check that the device is in place, a woman can press her fingertips over the skin in her arm where the device was placed; she should be able to feel the Implanon rod.

Women need to be clearly counseled on the unpredictable bleeding and spotting that occurs with Implanon, says Nelson. According to the patient package insert, the most common side effect of the method is a change in menstrual periods. Women should expect their menstrual periods to be irregular and unpredictable throughout the time they are using the method. Women may have more bleeding, less bleeding, or no bleeding, advises the insert. The time between periods may vary, and spotting may occur in between periods.

Progestin-only implant contraception options have been lacking since the 2000 removal of six-rod Norplant implant from U.S. pharmacy shelves. Wyeth Pharmaceuticals in Madison, NJ, suspended shipment of implants in August 2000 when concerns arose about efficacy of suspect lots. While the lots were found effective in July 2002, the manufacturer chose not to reintroduce the product in the United States.

The impact of Implanon in the United States is going to depend on how well it is covered by insurance programs and whether a foundation is established that makes Implanon available for those who cannot pay for it, says Robert Hatcher, MD, MPH, professor of gynecology and obstetrics at Emory University School of Medicine in Atlanta.

"More than 1 million women become pregnant each year while depending on birth control pills," he observes. "We desperately need several extremely effective, safe, and inexpensive long-term methods."

References

1. Creinin MD, Clark B. The latest contraceptive option: The single-rod implant. Contemporary OB/GYN 2005; accessed at: www.contemporaryobgyn.net/obgyn/article/articleDetail.jsp?id=178617&pageID=4.

2. Funk S, Miller MM, Mishell Jr DR, et al. Safety and efficacy of Implanon, a single-rod implantable contraceptive containing etonogestrel. Contraception 2005; 71:319-326.

3. Beerthuizen R, van Beek A, Massai R, et al. Bone mineral density during long-term use of the progestogen contraceptive implant Implanon compared to a non-hormonal method of contraception. Hum Reprod 2000; 15:118-122.

4. Hatcher RA, Zieman M, Cwiak C, et al. A Pocket Guide to Managing Contraception. Tiger, GA: Bridging the Gap Foundation; 2005.