United States of America. The Food and Drug Administration has approved a marketing application for the Preven Emergency Contraceptive Kit (Gynetics) containing the oral contraceptive pills for postcoital emergency contraception, packaged with a urinary pregnancy test.
The application is based on a regimen - also known as the Yuzpe regimen - that consists of two oral contraceptive pills containing ethinyl estradiol and levonorgestrel taken within 72 hours of unprotected intercourse and two pills taken 12 hours later. When used in this manner, the treatment is about 75% effective in preventing pregnancy.
The most common adverse effects are nausea, vomiting, menstrual irregularities, breast tenderness, headache, abdominal pain and cramps, and dizziness.
Although emergency contraception is not as effective as proper use of a regular contraceptive method, it substantially reduces the chances of becoming pregnant when used within 72 hours after unprotected sexual intercourse.
[See also p.9 above - levonorgestrel]
References: FDA Talk Paper T98-49 dated 2 September 1998.