Description
Norplant consists of a familiar ingredient in a new package. Six silicone rubber capsules about the size of matchsticks contain a synthetic progestin hormone long used in birth control pills. The flexible tubes are inserted in a fan-like arrangement and can be felt but not easily seen. Once in place, they steadily release a low dose of hormone into the bloodstream.
Effective within 24 hours after insertion, Norplant can continue to prevent pregnancy for up to five years. The hormone usually inhibits ovulation so that eggs are not produced regularly, and causes the mucus of the cervix to thicken, making it more difficult for sperm to reach the egg. Other ways that Norplant may provide contraceptive effects have been proposed but not proven.
Drawbacks
Because Norplant is not a barrier contraceptive, it offers no protection against sexually transmitted diseases such as AIDS, herpes, chlamydia, and gonorrhea. For optimum protection from both disease and pregnancy, couples may choose to use both Norplant and a condom.
Side effects that women have reported with the implant during the first year include irregular menstrual bleeding, headache, nervousness, depression, nausea, dizziness, skin rash, acne, change of appetite, breast tenderness, weight gain, enlargement of the ovaries, and excessive growth of body or facial hair.
Some Norplant users have also reported breast discharge, vaginal discharge, inflammation of the cervix, abdominal discomfort, and muscle and skeletal pain. These effects, however, cannot be linked to use of the implant because the complaints are common among the general population and could stem from other causes. There is no known biological reason to link the complaints specifically to use of the contraceptive.
By far the most common side effect is menstrual cycle irregularity. Over a five-year period of use, about 45 percent of women will have irregular periods, and another 45 percent will have normal periods. The remaining 10 percent will experience long periods of time - three to four months - with no bleeding.
The bleeding irregularities result from the continuous hormone release. With the oral contraceptive pills, estrogen and progestin are taken for three weeks and withdrawn for one week, causing regular bleeding. Norplant, on the other hand, provides no cyclic withdrawal and thus each individual creates her own bleeding pattern.
Other side effects commonly associated with use of Norplant include headaches, nausea, dizziness and nervousness.
The FDA's ongoing analysis of adverse reaction reports and postmarketing surveillance studies have found no basis for questioning the safety and effectiveness of Norplant when the product is used as directed in the labeling. The FDA's review assessed the safety and effectiveness of both the hormone levonorgestrel for long-term contraception and the safety of Norplant's silicone-based delivery system.
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