Manufacturers of both drugs accused of downplaying potential health risks
Just this week,
Depo Provera and Norplant made the news -- only not in a way that the manufacturers might like.
Animal studies conducted in New York City found that the synthetic hormone used in the contraceptives caused a 500 percent increase in the risk of HIV. Because it thins the lining of the uterus, women have less natural resistance to HIV-carrying sperm. Although the study was small scale, the results were frightening: 14 of the 18 monkeys were infected.
It is particularly bad news for women in developing nations, where AIDS is rampant -- and where both contraceptives are used heavily. Should these millions of women switch to a safer version of birth control? "From the data we have to date," a United Nations administrator told Newsday, "we believe there is no reason for changing contraceptive recommendations yet." Nonetheless, he added, international family planning agencies "have to be extremely alert and vigilant" following this research.
Whether women seeking Norplant or Depo -- and more importantly, women already using these methods -- will learn about these new developments is another matter. The manufacturers of both drugs have been accused of downplaying potential health risks, and health care providers, particularly in the Third World, are often cheerleaders for these long-lasting contraceptives.
But before those questions can be explored, an introduction is needed: what are Depo Provera and Norplant, and what other risks exist?
What are Depo Provera and Norplant?
and Norplant are forms of progestin -- a human-made version of progesterone, the hormone that prepares the uterus for pregnancy. Progestin is also an active ingredient in some oral contraceptives. It works by thickening the normal cervical mucus, which makes it harder for the sperm to penetrate. It also causes the uterus to develop a shallow lining and inhibits other hormones that help the ovaries develop eggs.
According to the manufacturers, both drugs are almost 100 percent effective in preventing pregnancy, and the risk factors for both are about the same. But besides that, the two drugs are really quite different.
Depo Provera is administered as a shot, injected into the arm or buttock, where it becomes a crystal and released into the bloodstream over a span of several months. Each shot is effective for slighly over 90 days, although women are usually re-scheduled for their next shot at precise three month intervals. (The literature provided by Upjohn does not mention this "safety margin.") Once Depo is injected, its effects cannot be reversed except by time. Some women find it takes an average of 10-12 months after the last shot before they can conceive. In some cases, fertility never returns.
Norplant is a set of six matchstick-sized capsules implanted under the skin in a woman's arm for up to five years. This time-released delivery makes Norplant unique, and is also the source of much of the controversy.
While the capsules can be inserted in about 15 minutes at a doctor's office and requires only a local anesthetic, removal is sometimes difficult. If the capsules were inserted too deeply or scar tissue has grown around the implant, minor surgery may be required. The manufacturer states that slightly over 6 percent of women have such problems, but it is thought to be much higher in the Third World.
Health risks of Depo and Norplant
During their first
year on Depo, most women gain more than 5 pounds, and many continue this weight gain as long as they are using the drug. Women on Depo often have more days of light bleeding in the first year, followed by amenorrhea (no periods) after using it more than a year. Norplant uses a different form of progestin that tends to cause ongoing irregular bleeding.
Like the Pill and other hormone-based contraceptives, some research shows that Depo causes bone mineral loss which can lead to osteoporosis later in life, particularly when the drug is administered to growing young women. High Density lipoprotein (HDL) cholesterol levels also fall significantly, which reduces protection against cardiovascular disease. Blood clots and a reduction in lipid levels can lead to heart attacks or strokes. But no randomized clinical trial has been conducted directly comparing the effects of Norplant to the Pill for cardiovascular risk.
According to the manufacturer, women at risk for breast cancer, strokes, phlebitis, or liver disease should not use Depo Provera. Depo has also been linked to cervical cancer in some research as well as glucose intolerance, which is dangerous for diabetics. A recent study suggests women using Depo have twice the normal risk of breast cancer, possibly because it accelerates the growth of already existing (but undetectable) tumors.
Depo also has potential health benefits. Some studies show Depo helps women with anemia and sickle-cell disease. Another selling points is that women who cannot tolerate estrogen found in oral contraceptives can use Depo.
Risks for Norplant are nearly identical, with the additional possibilty of complications during removal of the implants. While Norplant users have only a 2 percent risk of pregnancy, the pregnancies that do occur are much more likely to be ectopic (outside the uterus), which often requires major surgery -- an important risk not mentioned in literature given to women considering Norplant. The longer a woman uses Norplant, the dangers of such complications may increase. Ectopic pregnancies are not considered a problem with Depo because that drug usually causes menstruation to stop.
The majority of American women who use Norplant or Depo are pleased with the contraceptives, particularly at the beginning. Again, the literature distributed by the manufacturers is not completely truthful.
"Another measure of patient acceptances comes from a survey of 2,335 women during their first year of use. Nine out of 10 said they would be likely to recommend the Norplant system to a friend," reads a brochure distributed by the manufacturer. [Emphasis added.] But Norplant's popularity drops over time. Over the four years examined in a recent Florida study, acceptance was as low as 73 percent. Each year, about 10 percent of the women in the Florida study group had Norplant removed, mostly because of side effects. More recent reports show much higher dropout rates, but can likely be attributed to negative publicity surrounding the class action lawsuit.
Provera is the older of the drugs, derived from an injectable form of progestin first created in 1953. The Upjohn Company synthesized a version a few years later, and first applied for FDA approval in 1967. It was first developed as an inexpensive and impermanent alternative to sterilization for older women who did not want any more children. It had been in use in the U.S. for years before its 1992 FDA approval as a contraceptive, and was used to treat certain kinds of cancer and believed to prevent miscarriages. Last year about 9 million women used Depo, including 2 million in the United States.
Norplant was developed by the Population Council, a U.S.-based research organization that works with international family planning agencies. The organization still collects royalties on Norplant sales. Safety and efficacy studies began in 1972, with Norplant approved by the FDA in 1990. It has been used by about 1 million American women and 2.5 million worldwide, and is sold by pharmaceutical company Wyeth-Ayerst.
Albion Monitor May 5, 1996 (http://www.monitor.net/monitor)
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