EXECUTIVE SUMMARY
The contraceptive implant Nexplanon and its forerunner, Implanon, offer top-tier effectiveness against unintended pregnancy. Clinicians need to be able to identify appropriate candidates, present counseling tips on the contraceptive and noncontraceptive benefits, and recognize and treat side effects and rare complications.
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Nexplanon, as well as Implanon, is labeled with a duration of action of three years. However, data from several sources indicate that the device is effective for longer than that time period.
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The U.S. Medical Eligibility Criteria For Contraceptive Use Lists Few Medical Conditions That Contraindicate The Use Of Implants. There Are No Restrictions On Implant Use Based On Age, Smoking, Hypertension, Migraine Without Aura, Uterine Fibroids, Diabetes, Gallbladder Disease, Or Sickle Cell Anemia.
The contraceptive implant Nexplanon (Merck, Whitehouse Station, NJ) offers top-tier effectiveness against unintended pregnancy. How can you identify appropriate candidates, present counseling tips on the contraceptive and noncontraceptive benefits, and recognize and treat side effects and rare complications?
The implant provides “unsurpassed contraceptive efficacy,” says Anita Nelson, MD, professor emeritus in the Obstetrics and Gynecology Department at the David Geffen School of Medicine at the University of California in Los Angeles. Nelson presented on the subject at the 2016 Contraceptive Technology conference.1
The implant, a single rod (4 cm by 2 mm) made of ethylene vinyl acetate, contains 68 mg of etonogestrel. Its mechanism of action is through ovulation suppression and thickened cervical mucus, notes Nelson. In U.S. trials, just six pregnancies were recorded in 20,648 cycles, she states.
Nexplanon, as well as its forerunner, Implanon, is marketed with a duration of action of three years. However, data indicate that the device is effective for longer than that time period. Three studies in which 275 women used Implanon for longer than three years found no pregnancies during the fourth year of use.2
This research was corroborated by findings published in 2015 by researchers at the Washington University School of Medicine in St. Louis. Their initial analysis of data indicates that hormonal intrauterine devices (IUDs) and contraceptive implants remain highly effective one year beyond their approved duration of use.3 (Contraceptive Technology Update reported on the data. Readers can see the May 2015 article, “Intrauterine device and implant are effective beyond use approved by the FDA,” which can be accessed online at http://bit.ly/1rKxWTj.)
Who can use method?
The U.S. Medical Eligibility Criteria for Contraceptive Use (US MEC) lists few medical conditions that contraindicate the use of implants (Category 3 or 4):
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unexplained, unevaluated abnormal vaginal bleeding;
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systemic lupus erythematosus or unknown antiphospholipid antibodies;
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severe (decompensated) cirrhosis;
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benign or malignant liver tumor;
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current or past breast cancer;
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use of ritonavir-boosted protease inhibitors, certain anticonvulsants (phenytoin, carbamazepine, barbiturates, primidone, topiramate, oxcarbazepine), rifampicin, or rifabutin.4
There are no restrictions on implant use based on age, smoking, hypertension, migraine without aura, uterine fibroids, diabetes, gallbladder disease, or sickle cell anemia.2 No examinations or laboratory tests are needed to determine whether a woman is eligible to use implants, except in women with lupus.2
Insertion of an implant may occur at any time during the menstrual cycle as long as pregnancy may be reasonably excluded. Backup methods of contraception, such as use of a condom, should be used for seven days after insertion, unless the device is inserted within five days of initiating menses, immediately after childbirth or after abortion, or immediately upon switching from another hormonal contraceptive.5
If switching from use of an intrauterine device not near menses, Nelson advises abstinence/second method for seven days prior to removal and implant placement.
How about bleeding?
Like all progestin-only methods, Nexplanon causes vaginal bleeding in a large proportion of women. The bleeding pattern experienced during the first three months is broadly predictive of future bleeding patterns for many women. Effective preinsertion counseling on the possible changes in bleeding patterns may improve continuation rates, research indicates. Half of women with unfavorable patterns in the first three cycles will improve with time.6
Between 6% and 12% of implant users in contraceptive studies report weight gain; however, few discontinue the implant due to weight change.7 Studies suggest the overall implant removal rate because of weight gain varies from 3% to 7%.7
Research indicates that overall, 15% of women using implants report acne; however, only 1% had the im-plant removed for this reason.8
The message for clinicians is that implants and intrauterine devices provide top-tier contraception, says Nelson. Pills, patches, rings, and the contraceptive injection have 21 times higher pregnancy risk, she notes.
“Eliminate all barriers to access,” says Nelson. “Counsel effectively, and provide method same day as visit.”
REFERENCES
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Nelson AL. Implant update. Presented at the 2016 Contraceptive Technology conference. San Francisco, March 2016; Boston, April 2016.
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Raymond EG. Contraceptive implants. In: Hatcher RA, Trussell J, Nelson AL, et al. Contraceptive Technology: 20th revised edition. New York: Ardent Media; 2011.
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McNicholas C, Maddipati R, Zhao Q, et al. Use of the etonogestrel implant and levonorgestrel intrauterine device beyond the U.S. Food and Drug Administration-approved duration. Obstet Gynecol 2015; 125(3):599-604.
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Centers for Disease Control and Prevention. U.S. medical eligibility criteria for contraceptive use. Morb Mortal Wkly Rep MMWR 2010; 59(RR04):1-86.
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Makarainen L, van Beek A, Tuomivaara L, et al. Ovarian function during the use of a single contraceptive implant: Implanon compared with Norplant. Fertil Steril 1998; 69:714-721.
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Mansour D, Korver T, Marintcheva-Petrova M, et al. The effects of Implanon on menstrual bleeding patterns. Eur J Contracept Reprod Health Care 2008; 13 Suppl 1:13-28.
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Darney P, Patel A, Rosen K, et al. Safety and efficacy of a single-rod etonogestrel implant (Implanon): Results from 11 international clinical trials. Fertil Steril 2009; 91:1646-1653.
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Urbancsek J. An integrated analysis of nonmenstrual adverse events with Implanon. Contraception 1998; 58(6 Suppl):109S-115S.
