A new drug that can prevent pregnancy after unprotected intercourse or the failure of other contraception was approved on Friday by the FDA.
The drug, ulipristal acetate (to be sold under its brand name, ella), is available only by prescription and prevents pregnancy when taken orally within 120 hours (five days) after a contraceptive failure or unprotected intercourse. Previously approved emergency contraception based on the drug levonorgestrel (Plan B) is labeled for use within 72 hours of intercourse.
In two Phase 3 studies, researchers showed that ella significantly reduced the risk of pregnancy in women who used it after unprotected intercourse, according to the Food and Drug Administration (FDA). (Phase 3 studies examine the effectiveness of a drug or device and are the last step before seeking FDA approval.)
The drug likely inhibits or delays ovulation by preventing the rupture of the egg-containing follicle within the ovary – which is needed for an egg cell to be released from an ovary – when taken just before ovulation is to occur.
The drug is not intended for routine use as a contraceptive, according to Paris-based manufacturer Laboratoire HRA Pharma, and has been available in Europe since May 2009 under the brand name ellaOne.
Critics have said that women seeking emergency contraception up to 72 hours after the fact should be given levonorgestrel instead of the new drug, because levonorgestrel is cheaper and just as effective over that time period. Women would be "ill-advised" to take the new drug during that time period instead of the existing alternative, according to Gilda Piaggio, who was responsible for research on emergency contraception when she worked at the World Health Organization, writing in the May 8 issue of the journal The Lancet.
The side effects most frequently observed with the new drug during the clinical trials include: headache, nausea, abdominal pain, pain or discomfort during menstruation, fatigue and dizziness. They are similar to those of levonorgestrel emergency contraception.
The drug is manufactured by Paris-based Laboratoire HRA Pharma, and will be distributed in the United States by Watson Pharma Inc., of Morristown, N.J.