New review focuses on emergency contraception
When it comes to emergency contraception (EC), what does your clinic offer? A new review has found that mifepristone is the most effective EC method to prevent unwanted pregnancy; however, the drug has not gained U.S. regulatory approval for that use.1
To perform the analysis, researchers evaluated the results of 81 clinical trials that encompass the experience of 45,842 women who sought EC after one act of unprotected intercourse. The trials included in the review compared the effectiveness of mifepristone and levonorgestrel hormonal pills, the Yuzpe regimen (a method of combined hormone pills, repeated once 12 hours apart), and the copper intrauterine device (IUD).
Most of the clinical trials studied mifepristone in two levels: low dose (less than 25 mg) and middle dose (25 mg to 50 mg). Levonorgestrel trials included a single dose of 1.5 mg or two doses of 0.75 mg given 12 hours apart. The reviewers found mifepristone, given in the middle dose, was the most effective hormonal regimen in preventing pregnancy.
Reviewers found that more pregnancies occurred with levonorgestrel EC than with mid-dose mifepristone or low-dose mifepristone. Single-dose levonorgestrel EC had the same effectiveness as the split dose, report researchers; levonorgestrel, however, was more effective than the Yuzpe regimen in preventing pregnancy.1
Based on the review of current evidence, mifepristone should be the first choice of hormonal EC where available, reviewers concluded. If it is not available, single-dose levonorgestrel (1.5 mg) should be offered, the reviewers state. Copper IUD insertion can be offered to women presenting too late for EC pills, who are not at risk of sexually transmitted diseases, and who prefer long-term contraception, researchers conclude.
What do you use?
Family planning providers are most familiar with Plan B (Barr Pharmaceuticals; Pomona, NY), the only dedicated EC drug on the U.S. market. Since the company began distributing the over-the-counter version of the drug in November 2006, sales of the drug have soared. All national pharmacy chains now stock it, and 2007 estimates for Plan B sales were pegged at $80 million, almost double its 2006 figures.2
Plan B consists of two doses of 0.75 mg levonorgestrel, taken 12 hours apart. Studies have shown that a single 1.5 mg dose is as effective as two 0.75 mg doses 12 hours apart.3,4
When Plan B is not available, certain types of combination oral contraceptives can be used as EC. A total of 23 brands of combined oral contraceptives are approved in the United States for use as EC.5
Emergency insertion of a copper IUD is more effective than use of EC pills.5 Research results indicates use of the IUD method reduces the risk of pregnancy following unprotected intercourse by more than 99%.6 Guidelines issued by the World Health Organization allow IUDs to be inserted up to Day 12 of the menstrual cycle with no restrictions and at any other time in the cycle if it is reasonably certain that the patient is not pregnant.7
Mifepristone in the United States?
Providers are familiar with mifepristone in its use in medication abortion. The drug is marketed in the United States as Mifeprex (Danco Laboratories, New York City). Is the company planning to seek federal regulatory approval of the drug for use in emergency contraception?
"Danco does not at this time have plans to pursue use of Mifeprex as an emergency contraceptive," says Abigail Long, company spokeswoman.
What are some of the factors that may keep mifepristone from gaining acceptance as a method of emergency contraception in the United States? Beth Jordan, MD, medical director of the Association of Reproductive Health Professionals, observes, "I think some of the biggest factors are related to the fact that so many people continue to be confused by the fact that one drug can be used for many indications."
References
- Cheng L, Gülmezoglu AM, Piaggio G, et al. Interventions for emergency contraception. Cochrane Database of Systematic Reviews 2008; CD001324. DOI: 10.1002/14651858.CD001324. pub3.
- Crary D. Sales soar for morning-after pill. The Washington Post. Aug. 22, 2007: Accessed at www.washingtonpost.com.
- Von Hertzen H, Piaggio G, Ding J, et al. Low-dose mifepristone and two regimens of levonorgestrel for emergency contraception: A WHO multicentre randomised trial. Lancet 2002; 360:1,803-1,810.
- Arowojolu AO, Okewole IA, Adekunle AO. Comparative evaluation of the effectiveness and safety of two regimens of levonorgestrel for emergency contraception in Nigerians. Contraception 2002; 66:269-273.
- Trussell J, Raymond EG. Emergency contraception: A last chance to prevent unintended pregnancy. May 2008. Accessed at ec.princeton.edu.
- Trussell J, Ellertson C. Efficacy of emergency contraception. Fertil Control Rev 1995; 4:8-11.
- World Health Organization. Selected Practice Recommendations for Contraceptive Use. 2nd ed. Geneva; 2004.
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