The FDA has recognized only POPs and COCs with levonorgestrel or norgestrel for use as emergency contraceptives. However, a recent study found that COCs with norethindrone can be as effective as the standard Yuzpe regimen when used for EC.^13,14

Because of the estrogen content in COCs, nausea is common when they are used for EC, and an anti-emetic medication should be offered for pretreatment. Anti-emetics should be taken at least 30 to 60 minutes before the first COC dose; 25 to 50 mg of meclizine (Antivert) may be a particularly good choice because of its 24-hour duration of action compared to shorter acting anti-emetics such as dimenhydrinate (Dramamine), trimethobenzamide (Tigan), and promethazine (Phenergan).

The cost of one cycle of COCs varies and may be as high as $50.^4,12

How do emergency contraceptives work?

The exact mechanism of action for oral EC regimens is unknown. What is known is that when oral EC regimens are taken before ovulation, they work primarily by disrupting normal follicular development and egg maturation so that ovulation is delayed or prevented.⁴ A secondary way that EC may work when taken before ovulation is to alter the luteal phase and thicken cervical mucus. ⁴

When taken after ovulation, EC may interfere with any of the processes that occur during the approximately seven-day interval when sperm migrate, fertilization occurs, the fertilized egg is transported from fallopian tube to uterus, the uterine lining becomes receptive to the egg, and the corpus luteum maintains hormone levels necessary for implantation.⁴ EC may interfere by causing impairment of sperm function or altered transport of sperm, egg, or embryo or by altering the endometrial lining.⁴

Studies have found that levonorgestrel and the Yuzpe regimen suppress or delay the luteinizing hormone (LH) peak and inhibit follicle rupture.^15,16 Data support the belief that delay of ovulation is the primary mechanism of action of oral forms of EC, not inhibition of implantation of a fertilized egg.¹⁷

Table 2. Failure rates: Yuzpe vs. levonorgestrel

Although the Yuzpe regimen is effective at preventing pregnancy, levonorgestrel alone is more effective (Table 2). In one 1998 study, the overall pregnancy rate (failure rate) with levonorgestrel was 1.1%, compared with 3.2% for the Yuzpe regimen.¹⁸ In addition, those who took the Yuzpe regimen experienced more side effects compared to those taking levonorgestrel.¹⁸ A second study found that both regimens were more effective if treatment was started sooner rather than later. When the first dose of EC was delayed by 12 hours, the odds of pregnancy increased by 50%.¹⁹

The original Yuzpe regimen of COCs was empirically based, in terms of dosage and timing. Newer effective regimens have been studied that include extending the treatment period from 72 hours to 120 hours after unprotected intercourse; using combination COCs with norethindrone instead of levonorgestrel or norgestrel; administering a single dose of the Yuzpe regimen; and administering the total progestin-only regimen of levonorgestrel in a single dose.^10,11,14

Who should use emergency contraception?

Table 3. When might emergency contraception be needed?

EC is recommended for any woman of reproductive age who wants to lower her risk of becoming pregnant after unprotected vaginal-penile intercourse—including cases of sexual assault⁴ —or inadequately protected intercourse. Examples include failure of the contraceptive method such as a broken condom, dislodged diaphragm or cervical cap, forgotten combination COCs, detached contraceptive patch, a removed vaginal contraceptive ring, late medroxyprogesterone acetate (Depo-Provera) injection, or failed withdrawal (Table 3).

When should EC not be used?

Contraindications to using POPs for emergency contraception are pregnancy and allergy to a component of the product. FDA labeling of Plan B includes undiagnosed abnormal genital bleeding as a third contraindication; as long as pregnancy is ruled out, however, EC can be given to an adolescent who is bleeding.^4,12

COCs carry more contraindications because of their estrogen component. Pregnancy, allergy, and acute current migraine with neurologic deficits are absolute contraindications to the Yuzpe regimen. Although a history of deep-vein thrombosis (DVT) and pulmonary embolism (PE) is an absolute contraindication for ongoing contraception with a COC, it is not a contraindication for prescribing the Yuzpe regimen for EC. However, the first choice in these clinical scenarios is a progestin-only EC regimen when it is available. The risk of a clot for a patient with a history of DVT or PE remains higher for pregnancy than for a single course of the Yuzpe regimen.^4,12

What about side effects and complications?

Side effects from POPs are minor and less frequent and less severe than those that occur with COCs, but adolescents seem inclined to report symptoms more often than adult women do. A recent study evaluated the tolerability of levonorgestrel EC (given in two doses) in 52 adolescent women and found that the most frequently reported side effects in the first week were headache (50%), nausea (38%), dizziness (27%), and fatigue (21%). The symptoms were reassessed in the second week after the medication was taken (when it would no longer be in the body): 33% reported headache; 19%, fatigue; 17%, lower abdominal pain; and 13%, nausea. Symptoms that were of significantly higher incidence in the first week were nausea (p=.001), fatigue (p=.002), headache (p=.004), and diarrhea (p=.004). Menses returned within seven days of the anticipated date in 63% of participants.²⁰

Side effects from COCs used for EC include usual symptoms from the estrogen component, such as nausea and vomiting. Nausea has been reported in 50% of women using the Yuzpe regimen, with vomiting occurring in 20%, whereas these symptoms are much less common in women taking progestin-only EC (23% and 6%, respectively).¹² Other common side effects of COCs include fatigue, dizziness, breast tenderness, stomachache, and moodiness.^12,14

Vaginal spotting is a side effect of both POPs and COCs. In one study among women who took the Yuzpe regimen or one of its variants, 10% had spotting, usually lasting one or two days, at some point before the next menses. There was no difference in the spotting rate between women who became pregnant following EC use and those who did not. Women who took EC in the first half of the menstrual cycle (before day 12) were more likely to have their next period earlier than expected (by longer than three days).²¹

As for complications, with 4 million doses of dedicated COC pills given for EC in the United Kingdom, just three cases of DVT and three cases of cerebrovascular disorder have been reported. None of these cases were clearly linked to the medication.²²

As EC has become more available, its use has increased, and new adverse events have been reported. Cases of ectopic pregnancy had been reported in association with the Yuzpe regimen; more recently, cases of ectopic pregnancy following levonorgestrel EC have been reported as well.²³ Recent data show reports of eight ectopic pregnancies for 4.4 million units of levonorgestrel product sold in the European Union—less than expected given a 3% failure rate of EC. These data do not support an increased risk of ectopic pregnancy following use of levonorgestrel EC.²⁴ Because levonorgestrel is very effective at preventing pregnancy, it is possible that the ectopic rate among women who take levonorgestrel as EC is lower than it would be among women who do not use EC. Prior ectopic pregnancy is not a contraindication to EC use. However, among women who have a history of ectopic pregnancy, it is prudent to confirm that EC was effective by performing a pregnancy test two weeks after the emergency contraceptive was taken.

Another recent finding is that a woman's risk of pregnancy is particularly high if she has unprotected intercourse soon after taking EC. Two studies of mifepristone, which is not available for EC in the US, found that women who had unprotected intercourse after taking EC, but before menses, had 12 to 28 times the risk of pregnancy.^25,26 These studies demonstrate the importance of counseling young women who take EC about the rapid return of fertility and the need for interim abstinence or immediate initiation of contraception.

How does EC affect sexual and contraceptive behavior?

There is concern that access to EC may lead women to have unprotected intercourse more often and to use regular contraceptive methods less often.²⁷ Eight studies demonstrate that these concerns are unfounded. Five of these studies were conducted with groups of adult women and found that women in the advance provision groups—those that received a supply of EC in advance—were more likely to use EC (although not repeatedly) and to use it sooner. The advance provision group had a lower pregnancy rate in one of the studies, but a similar pregnancy rate in another. Moreover, the advance provision groups used other methods of contraception, such as condoms, at the same rate as the control group and, in one study, were not more likely to change to a less effective method of birth control. Both groups had the same frequency of unprotected intercourse.^28-32

Three studies assessed the impact of providing advance EC on adolescents' behavior. In one four-month study of women 16 to 24 years old, those in the advance provision group were almost three times as likely as those in the control group to report using EC. Almost half the women (46%) reported using the same contraceptive method at enrollment and at follow-up four months later. The percentage of young women who reported "never had unprotected sex" increased from enrollment to follow-up (33% versus 56%). At follow-up, however, women in the control group were more likely to report consistent oral contraceptive use than women in the advance supply group.³³

In a second advance provision study with adolescents (15 to 20 years old), follow-up interviews at one and six months revealed no differences between the advance EC and control groups in reported unprotected sex within the past month or at last intercourse. Additionally, these interviews found no significant differences by group in hormonal contraception use at past month or last intercourse. A higher past-month condom use was reported among the advance provision group at the six-month follow-up. At the one-month follow-up, the advance group reported nearly twice as much EC use as the control group, and the advance provision group used EC sooner after unprotected intercourse compared to the control group.³⁴

In the most recent advance provision study, published in 2005, investigators assessed the sexual and contraceptive behaviors of women age 15 to 24 years who were randomized to one of three EC access groups: advance provision (with three packs of EC), pharmacy access, or clinic access (control group). Those in the advance provision group were almost twice as likely to use EC as those in the clinic access group at six-month follow up. However, the pharmacy access group was not more likely to use EC compared to the clinic access group. The advance provision group did not have a significantly higher frequency of unprotected intercourse compared to the clinic access group. No differences in contraceptive or condom use or other sexual behaviors were found by group.

At the six-month follow up, 8% of young women in the study had become pregnant and 12% had acquired a sexually transmitted infection (STI). There was no reduction in pregnancies or increase in STIs by group (advance provision, pharmacy access, or clinic access).³⁵

How can you improve access to EC?

Some European countries and, recently, Canada have allowed levonorgestrel EC to be sold over the counter. Efforts have been under way to make Plan B an OTC medication in the US. In April 2003, an application was submitted to the FDA for OTC status. That December, two FDA committees voted 23 to 4 in favor of Plan B being made available OTC. But the FDA rejected the application in May 2004, citing insufficient information about how younger adolescents would use EC if it were available OTC.

Two months later, Barr Laboratories submitted an application for a unique and unprecedented dual prescribing status, requesting that Plan B be OTC for women age 16 and older but prescription-only for younger females. The FDA announced its response to the application in August 2005: Available scientific data are sufficient to support the safe use of Plan B as an OTC product, but only for women 17 years and older.

No final decision was made, however, because the FDA has not determined whether a drug can be both prescription and OTC at the same dosage based on the age of the person using the drug. A related concern is how, as a practical matter, an age-based distinction could be enforced. For 60 days, public comments on the issues of marketing both a prescription and OTC version of the same active ingredient in a single package, and of enforcement of the age limitation, were taken. The time for public comment ended in November 2005. As of January 17, 2006, no further action had been taken by the FDA. Pediatricians can increase access to EC by supporting OTC approval of Plan B as has been recommended by the American Academy of Pediatrics (AAP),³⁶ the Society for Adolescent Medicine,³⁷ and the American College of Obstetrics and Gynecology.³⁸

Common questions you may have about emergency contraception

At least 35 states allow pharmacists to develop collaborative practice agreements with physicians that may involve approving refills and initiating and changing certain medication regimens. As of January 2006, pharmacists in six states—Alaska, California, Hawaii, Massachusetts, New Hampshire, and Washington—had collaborative practice agreements specifically for EC. Pharmacists in California, Maine, and New Mexico have independent prescribing authority for EC.³⁹ Pediatricians in states that allow these agreements can increase access to EC for adolescents by developing collaborative agreements with pharmacists.

Because the efficacy of EC depends on how soon it is taken after unprotected intercourse, it is critical for patients to be aware of EC and how to obtain it promptly. Pediatricians and their staff can inform adolescents and provide information about EC at both well and sick visits. You can, for example, create a patient information handout with your contact information and give it to patients individually or place it in the examination rooms (or use the Guide for Patients). The AAP has created a fact sheet for parents and adolescents about EC that is available on its Web site (www.aap.org); see the resource listing.

Sample letter to send to local pharmacies

Anticipatory guidance should include discussions about the adolescent's interest in sexual activity and plans for future sexual activity. Teach both male and female adolescents about EC, as it is the responsibility of both to prevent unintended pregnancy. Also counsel virginal teens about the existence of EC, because adolescents often fail to plan ahead and use contraception during their first sexual experience. Providing information about EC, similar to providing information about other contraceptives, does not encourage adolescents to initiate sexual activity but encourages them to engage in safer sexual behaviors if they have made the decision to be sexually active. Counseling about abstinence as a contraceptive option should always accompany discussions about any type of contraception.

Requests for EC from adolescents can facilitate visits for contraceptive education and identify youth requiring routine gynecologic care and screening for STIs. In addition, counseling adolescents about EC conveys that you are interested and willing to provide contraceptive education and reproductive health-care services. Making sure that nursing and support staff understand that this confidential service is provided in the office will also help adolescents feel more comfortable obtaining EC.

Emergency contraception: A resource list

Another way to increase access to EC is to provide a sample of Plan B or a prescription for it in advance. When writing a prescription for Plan B, write instructions for both tablets to be taken at the same time as soon as possible after unprotected intercourse and within five days. Patients should be encouraged to fill the prescription so they have it on hand if needed and should be instructed to check the expiration date on the pill package to see if the tablets have expired before taking them. Patients should also be encouraged to make an appointment for follow up two weeks after taking EC to ensure pregnancy was avoided and, possibly, to be tested for STIs.

Although many pharmacists are dedicated to assisting women in filling prescriptions that have been written for them, some may not be willing or able to dispense EC. A pharmacist may work for a corporation that has decided not to stock EC (Plan B), such as Wal-Mart, or for an independent pharmacy where the pharmacy manager has decided not to carry the medication. Some pharmacists work in settings where Plan B is available but have a personal objection to dispensing it. If this is the case, some, but not all, pharmacies have a mechanism in place to ensure that the patient gets the needed medication.

You can improve access to EC for adolescents by knowing which pharmacies stock Plan B and employ a pharmacist who is willing to dispense it. Consider sending a letter to local pharmacies asking if they dispense EC and then compile a list of pharmacies where you can refer adolescents to fill prescriptions for EC (see the sample letter to pharmacists).

An approach to providing EC in the office

Screen each female adolescent by asking if she has ever been sexually active or plans to be in the near future. For adolescents who are not sexually active, counsel about abstinence and other forms of contraception. Explain EC and offer an advance prescription for Plan B.

If the adolescent is already sexually active, ask when she had her last menses, when she last had intercourse, and what method of contraception was used. If she has had unprotected intercourse within the last five days, or if she comes to the office requesting EC within that time frame, perform a urine human chorionic gonadotropin pregnancy test to rule out pregnancy.

If the urine pregnancy test is negative, ask the patient if she wants to avoid pregnancy and (assuming she does) review EC: how it works, efficacy and failure rate, potential side effects. Plan B may be prescribed over the telephone for patients who cannot come to the office in a timely manner. Advise the patient to remain abstinent for two weeks after she takes EC and to schedule a two-week follow-up appointment to make sure she has not become pregnant.

At the visit at which you dispense EC and at the follow-up visit, discuss a contraceptive plan for the future. Review options, including abstinence, oral contraceptive pills, the contraceptive patch, the vaginal ring, Depo-Provera, and condoms (alone or with vaginal spermicide).

At the follow-up appointment, consider performing a pelvic exam to rule out exposure to STIs (including tests for gonorrhea and chlamydial infection and a wet mount for Trichomonas). Such an exam is unnecessary before prescribing EC unless the patient has symptoms of an STI. Symptoms that indicate the need for pelvic examination include urinary frequency, urgency, or dysuria; intermenstrual or postcoital vaginal bleeding; dyspareunia or pain on intercourse; pelvic pain; vaginal itching; and unusual vaginal discharge or odor.

Bringing the benefits to patients

Emergency contraception is a safe and effective form of pregnancy prevention that can be used after underprotected or unprotected intercourse. Adolescent women can have a second chance to prevent unintended pregnancy if pediatricians improve access to EC. (See "Commonly asked questions about emergency contraception".)

Pediatricians can reduce unintended adolescent pregnancy by:

• routinely counseling adolescents (male and female) at all office visits (sick and well) about the existence of EC
• providing easy access to EC by prescribing it in advance or over the telephone
• identifying which pharmacies carry the medication.