It’s surprising to realize that the birth control pill, which launched a revolution in women’s sexuality and health, has been around for less than 50 years—especially considering the myriad of methods and products on the market today. New types of contraceptives have become available, more are on the way, and noncontraceptive benefits continue to accrue. This article reviews noteworthy changes and upcoming products.
When it was introduced in 1960, the oral contraceptive (OC) consisted of 20 or 21 active pills followed by a pill-free interval of 7 or 8 days. No medical reason justified the pill-free interval; it was devised simply to trigger menses and reassure the woman she was not pregnant.
That pill-free interval shrank as we gained awareness of the benefits of continuous OC regimens, particularly in the treatment of endometriosis. Advantages—well documented by Sulak1—include marked reduction or elimination of menses-related symptoms such as menorrhagia, dysmenorrhea, and menstrual migraines.
Continuous OCs became “official” in 2003 with the introduction of Seasonale (ethinyl estradiol, 0.03 mg/levonorgestrel, 0.15 mg), a continuous regimen taken for 84 days, followed by a 7-day pill-free interval.2
This regimen reduces the number of periods to 4 each year.
Breakthrough bleeding diminishes over time. Although breakthrough bleeding is a common side effect of continuous oral contraception—as it is with conventional regimens—it decreases with each successive cycle of Seasonale. By the fourth cycle, it is comparable to the level reported by women on a conventional regimen. Prolonged and heavy bleeding also can be managed by discontinuing pills for 7 days.
Other methods also can be used continuously. Continuous contraception is not limited to oral contraception.
The contraceptive ring (Nuvaring; ethinyl estradiol/etonogestrel) can be left in place for 4 weeks instead of 3 without decreasing efficacy. Both hormone levels are sufficient to prevent pregnancy throughout these weeks.3
Nor is there any reason to doubt the efficacy of continuous use of the contraceptive patch (Evra; ethinyl estradiol/norelgestromin).
New regimens. A regimen of 24 active pills and a 4-day pill-free interval is available in Europe. The shorter pill-free interval allows further reduction of the active components ethinyl estradiol and gestadene. This agent contains 15 μg estradiol per pill.4
A version of Yasmin that contains only 20 μg of ethinyl estradiol, should be released in the United States later this year. It will consist of 24 active pills and a 4-day pill-free interval.
New implantable rod. Implanon, a new single-rod contraceptive implant containing etonogestrel, is available outside the United States and may become available here in the near future.5,6 It can be inserted in 1.6 minutes, removed in 2.6 minutes, and lasts 3 years. No pregnancies were reported in clinical trials.
Lower dose of Depo-Provera effective for 3 months. A new dose and route of administration for Depo-Provera (depotmedroxyprogesterone acetate) is just as effective as the 150-mg intramuscular dose.
The new dose is 104 mg administered subcutaneously every 3 months. When it becomes available in the near future, this preparation should allow women to administer the drug at home.7
The different methods of emergency contraception are listed in a clip-and-save chart on page 46, which can be photocopied for convenient reference.
Trussell and colleagues’8 excellent review prefers the term emergency contraception to refer to contraceptive use after intercourse has occurred. The term “morning-after pill” is confusing because the method can be used any time after intercourse for up to 72 hours. It can even be used after 72 hours, albeit at reduced efficacy.
The Yuzpe regimen is the oldest and probably most popular form of contraception. It involves taking 2 Ovral tablets (ethinyl estradiol/levonorgestrel) followed by 2 more tablets 12 hours later. Each dose consists of 100 μg of estradiol and 0.5 mg of norgestrel.
Unfortunately, Ovral is not readily available in pharmacies. An alternative is taking enough OCs to equal the 100-μg dose of ethinyl estradiol and the 0.5 mg dose of norgestrel. For example, 5 tablets of Alesse or Levlite can be substituted for the 2 Ovral.
Efficacy is 75%. That is, if 100 women have unprotected intercourse once during the second or third week of their cycle, about 8 will become pregnant without treatment, and only 2 will become pregnant after treatment—a 75% reduction.
OCs that contain different progestins have not been studied extensively. They appear to work with lower efficacy than pills containing levonorgestrel.
- Common side effects include nausea and vomiting. Co-administration of an anti-nausea agent may be necessary. About 50% of women experience nausea and 20% vomit within 2 hours of taking a dose; some clinicians recommend repeating that dose to assure efficacy. One option is giving two 25-mg tablets of the over-the-counter drug meclizine 1 hour before combined emergency contraceptive pills; this reduces the risk of nausea by 27% and vomiting by 64%, but the risk of drowsiness doubles. Taking the medicine with a meal does not lower the rate of nausea.
- Contraindications. The only contraindication is an established pregnancy, since the drugs are taken so briefly.