contraceptives--postcoital and Hemorrhage

This multinational clinical trial compared the efficacy and side effects of single doses of 600 mg, 50 mg, and 10 mg of mifepristone in emergency contraception when given within 120 hours (5 days) of unprotected coitus. A total of 1717 women from 11 family clinics in six countries (Australia, China, Finland, Georgia, UK, US) were enrolled and randomly assigned to the 3 treatment groups (559 to 600 mg, 560 to 50 mg, and 565 to 10 mg). The study revealed that mifepristone treatment prevents 85% of expected pregnancies. It was also found that proportions of pregnancies were similar in the 3 treatment groups; 1.3% in the 600-mg treatment group, 1.1% in the 50-mg group, and 1.2% in the 10-mg group. Delayed menstruation was seen as the most significant side effect of the treatment (P 0.01) and was more likely to occur in women receiving the 600-mg treatment (36%); it occurred in about 23% of the women receiving 50 mg and in 18% of the women receiving 10 mg of mifepristone. Moreover, bleeding within 5 days of treatment was found to be significantly associated with the treatment dosage. Overall, bleeding occurred in 15%, 31%, and 35% of women who received 10 mg, 50 mg, and 600 mg of mifepristone, respectively. Other dose-related reactions included fatigue, weakness, nausea, vomiting, headache, and dizziness.

Topics: Biology; Contraception; Contraceptive Agents; Contraceptive Agents, Female; Contraceptives, Postcoital; Disease; Endocrine System; Family Planning Services; Hemorrhage; Hormone Antagonists; Hormones; Menstruation Disturbances; Mifepristone; Physiology; Research; Signs and Symptoms