Birth Control Overview (cont.)
Francisco Talavera, PharmD, PhD
Birth control pills
Birth control pills, also known as oral contraceptives, have been marketed in the United States since 1962. Over the past 40 years, there have been changes in the type of estrogen and progestin (hormones) used in the pills and lower amounts.
According to the Centers for Disease Control and Prevention, the birth control pill is the leading birth control method used by women younger than 30 years (17% use the pill).
Birth control pills today are designed to improve safety and reduce side effects. Lower doses of estrogen are associated with a decrease in side effects, such as weight gain, breast tenderness, and nausea.
Birth control pills are usually taken by mouth and swallowed with a liquid. In late 2003, the FDA approved a spearmint-flavored chewable birth control pill called Ovcon 35. They contain the same hormones that are in standard birth control pills. You may chew the pills or swallow them whole. If you chew the pill, you should drink 8 ounces of water afterward to make sure the full dose reaches your stomach.
Over 30 different combinations of birth control pills are available in the United States. The majority of the combinations of these pills have 21 hormonally active pills followed by 7 pills containing no hormones. A woman begins taking a pill on the first day of her period or the first Sunday after her period has begun. By taking a pill a day, a woman can usually take pills consistently throughout her cycle.
- Monophasic pills: These have a constant dose of both estrogen and progestin in each of the hormonally active pills.
- Phasic pills: These combinations can alter either or both hormonal components to try to mimic the natural menstrual cycle.
- 91-day pill: The FDA has approved a birth control pill that you take for 12 weeks (84 days) followed by 1 week (7 days) of an inactive pill. A menstrual period occurs during that week, every three months. The pills (known as Seasonale) contain the hormones already approved for other, 28-day birth control pills.
If a woman misses 1 or 2 pills, she should take 1 tablet as soon as it is remembered. She then takes 1 tablet twice daily until each of the missed pills has been accounted for. Women who have missed more than 2 consecutive pills should be advised to use a backup method of birth control at the same time, finishing up the packet of pills until her next period.
The pills prevent ovulation (release of an egg) and thus prevent pregnancy.
- How effective: Pregnancy rates range from 0.1% with perfect use to 5% with typical use.
- Advantages: Birth control pills are used to treat irregular menstrual periods. Women can manipulate the cycle to avoid a period during certain events, such as vacations or weekends by extending the number of intake days of hormonally active pills or by skipping the nonactive pill week. Birth control pills prevent certain conditions, such as benign breast disease, pelvic inflammatory disease (PID), and functional cysts. Functional cysts are reduced by the suppression of stimulation of the ovaries. Ectopic pregnancies are prevented by the cessation of ovulation. Birth control pills have been known to prevent certain ovarian and endometrial cancers.
- Disadvantages: Problems in taking birth control pills include nausea, breast tenderness, weight gain, breakthrough bleeding, no periods, headaches, depression, anxiety, and lower sexual desire. Birth control pills do not provide protection from STDs. It’s important to take the pills daily and consistently (same time every day). If a woman stops taking birth control pills, it may take her a few months to get her normal ovulatory cycle back. After 6 months, she may need to be examined by her health care provider.
- Additional risks: Some women may be at risk for blood clots (venous thrombosis). At particular risk are heavy smokers (especially those older than 35 years), women with high or abnormal blood lipids (cholesterol levels), and women with severe diabetes, high blood pressure, and obesity.
The association of birth control pill use and breast cancer
in young women is controversial. The Collaborative Group on Hormonal Factors in Breast Cancer performed the most comprehensive study to date in 1996. The results demonstrated that current pill users, and those who had used birth control pills within the past 1-4 years, had a slightly increased risk of breast cancer. Although these observations support the possibility of a marginally elevated risk, the group noted that the pill users had more breast examinations and breast imaging than the nonusers. Thus, although the consensus states that birth control pills can lead to breast cancer, the risk is small and the resulting tumors spread less aggressively than usual. Current thought is that birth control pill use may be a cofactor that can interact with another primary cause to stimulate breast cancer.
The relationship between birth control pill use and cervical cancer is also quite controversial. Important risk factors include early sexual intercourse and exposure to the human papillomavirus
. The thinking now is that if birth control pills increase the risk of cervical cancer, the risk is small and related to risky behavior. Thus, women who use birth control pills should have an annual Pap test.
Progestin-only birth control pills
Progestin-only pills, also known as the mini-pill, are not used widely in the United States. Fewer than 1% of users of oral contraceptives use them as their only method of birth control. Those who use them include women who are breastfeeding and women who cannot take estrogen.
Birth control patch
New in the United States is a transdermal patch (you wear it on your skin) that releases estrogen and progesterone directly into the skin (brand name: Ortho Evra). Each patch contains a 1-week supply of hormones. It releases a low daily dose equivalent to the lowest-dose oral contraceptive. It’s easy for women to use because it works for a week, and women don’t have to remember a pill every day. You apply a new patch every week for 3 weeks and do not wear a patch during the fourth week when you have a menstrual period. It is available by prescription.
Side effects are similar to those experienced by women using oral contraceptives. The patch may cause skin irritation where it is placed (near the bikini line or on the buttocks or upper body). Sometimes it may come off and not be noticed, for example, in the shower, and it will be less efficient. In August, 2002, the FDA listed a failure rate for the patch of 1 pregnancy per 100 women per year, similar to that of other combination methods. It may be less effective for women who weigh more than 198 pounds. The patch does not protect against STDs.
The vaginal ring (NuvaRing) is a new form of birth control. The actual design of vaginal rings as birth control was first developed in the 1970s. Vaginal rings can deliver progesterone or progesterone/estrogen combinations. The hormones are released slowly and absorbed directly by the reproductive organs. Preliminary studies show they safely prevent pregnancy, like birth control pills, with fewer side effects. These would be used in the same schedule as birth control pills, with 3 weeks of ring usage and 1 week without to produce a menstrual period. If the ring comes out on its own, and remains out for more than 3 hours, you must use another form of birth control until the ring has been back in place for at least 7 days. It is available by prescription. The vaginal ring does not prevent STDs.
The FDA approved contraceptive use of implants (levonorgestrel, brand name Norplant) in 1990. In 2003, the manufacturer decided not to continue marketing the Norplant System to health care professionals. The company will focus on developing other birth control options. Current users with medical questions may call the Norplant System Information Line at (800) 364-9809.
This method consists of inserting 6 silicone rubber rods about the size of matchsticks under a woman’s skin in her upper arm. They can be seen under the skin and felt.
The implant releases medication throughout the period of use and begins to work within the first 24 hours. Protection may be provided for 5 years. The hormone stops ovulation.
- How effective: Implants are as effective as surgical sterilization. Overall, pregnancy rates increase from 0.2% in the first year to 1.1% by the fifth year.
- Advantages: Implants last a long time. A woman can become fertile again once the implants are removed (again, surgically).
- Disadvantages: A minor surgical procedure is necessary to put them in and to remove them. Difficulty in removal is a disadvantage. Menstrual irregularities are common, along with other side effects, including weight gain, headaches, mood changes, growth of facial hair, flow of milk from nipples, and acne. This method does not protect against STDs.
- Additional risks: Implants are often used for women who have just had a child and are breastfeeding, for those who have trouble remembering to take birth control pills or use other birth control methods, and for women who should not get pregnant because of a medical condition. Implants are not recommended for heavy smokers, women with a history of ectopic pregnancy, diabetes, high cholesterol, severe acne, high blood pressure, heart disease, migraine, and depression.
Although the Norplant system is no longer available, a new single rod system using a form of the progestin desogestrel and providing 3 years of contraception is currently available in Europe (Implanon) and may soon be available in the United States.
An injection of a synthetic hormone depomedroxyprogesterone acetate (DMPA, brand name: Depo-Provera) can be given every 3 months to stop ovulation. You receive it by injection in the doctor’s office. After injection, the medication is active within 24 hours and lasts for 3 months. It prevents your ovaries from releasing eggs.
- How effective: DMPA is an extremely effective contraceptive option. Most other medications or a woman’s weight do not change its effectiveness. Within the first year of use, the failure rate is 0.3%.
- Advantages: DMPA does not produce the serious adverse effects of estrogen, such as blood clotting. It lowers risk for certain endometrial and ovarian cancers. Problem periods may become regular.
- Disadvantages: Some women may not have a period within the first year. Irregular bleeding can be treated by giving the next dose earlier or by adding a low-dose estrogen temporarily. Because DMPA lasts in the body for several months in women who have used it on a long-term basis, it can delay the return to fertility. About 70% of former users desiring pregnancy conceive within 12 months, and 90% of former users conceive within 24 months. Other adverse effects, such as weight gain, depression, and menstrual irregularities, may continue for as long as 1 year after the last injection. Recent studies suggest a possible link between DMPA and bone density loss. Results are conflicting and limited. This method does not protect against STDs.
One of the newest developments in contraception is a combined monthly injection (medroxyprogesterone
acetate [progesterone] and estradiol cypionate [estrogen], brand name: Lunelle). It recently received FDA approval in the United States. The injections stop ovulation like birth control pills do. They thicken cervical mucus to prevent sperm from traveling up the fallopian tubes to fertilize an egg and thin the uterine lining to prevent an egg from implanting.
Women who want to become pregnant may stop using Lunelle at any time. Some women have an immediate return to fertility. Others may have to wait 60-90 days to have normal menstrual cycles.
- How effective: When used correctly, Lunelle is 99.8% effective. One-year failure rates of less than 1% have been reported in clinical trials. In one US study of 782 women, there were no pregnancies after 1 year of use.
- Advantages: A woman can regain fertility after 2-3 months after the last injection. There are fewer users with problem periods or no periods. Lunelle can protect the uterus from cancer and endometriosis and reduce ovarian cysts and tumors.
- Disadvantages: Disadvantages include irregular spotting, weight gain, possible decrease in sexual desire, headache, and mild depression or mood changes. You are required to see your health care provider each month for the injections and may have to fill the prescription at the pharmacy and then take the medication with you to the provider for the injection. Injections are given every 28-30 days and no later than 33 days after the last injection. Timing is determined by the number of days, not your menstrual period. Some women may not have a period but should have the injection on schedule. In contrast to other hormonal contraceptive methods, due to its novelty, cancer risk is not known. More extensive worldwide use and additional studies may demonstrate the risk, if any, on cancer of the reproductive tract. Some women may experience changes in vision, especially for contact lens wearers. There is a higher risk of gallbladder
disease. Any woman with a history of blood clots, stroke, heart disease, breast cancer, unexplained vaginal bleeding, and high blood pressure should avoid this option. Women older than 35 years who smoke should not have these injections. This method does not protect against STDs.
Pharmacia, the drug's manufacturer, voluntarily recalled all prefilled syringes of Lunelle because of a production error that may have resulted in insufficient dosing on October 10, 2002. For more information on Lunelle, Pharmacia can be reached at (800) 323-4204.
Seek emergency medical care if you experience any of these symptoms:
A: Abdominal pain
Eye changes (blurred vision)
Severe thigh or calf pain
See Birth Control Hormonal Methods.
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