ULIPRISTAL ACETATE- A NOVEL ORAL EMERGENCY CONTRACEPTIVE: HYPE OR HOPE?

摘要

Unintended pregnancy is a global reproductive health concern. Although emergency contraception is meant to be used after an unprotected intercourse to prevent unwarranted pregnancies, available methods including levonorgestrel 1·5 mg, the currently gold standard EC regimen, is only effective if used as soon as possible after sexual intercourse and before ovulation. Ulipristal acetate (ellaOne in the European Union, ella in the U.S., HRA Pharma), a novel selective progesterone receptor modulator formulated as a 30- mg emergency contraceptive tablet with similar side effect profiles as levonorgestrel can prevent pregnancy within 120 hours (5 days) after an unprotected intercourse or contraceptive failure on account of its ability to inhibit or delay ovulation. It has been shown to prevent about 60% of expected pregnancies, which is comparable to that provided by levonorgestrel. Two phase 3 prospective, multicenter controlled clinical trials have already demonstrated the safety and effectiveness of ulipristal, according to the USFDA, whose advisory committee has voted unanimously in favor of approving the new drug application in August 2010. However, the findings from a very recent randomized non-inferiority trial comparing the efficacy and safety of ulipristal acetate with levonorgestrel for emergency contraception, has been questioned by scientists and statistical consultants all around the globe based on the premature and misleading conclusions due to lack of sufficient sample size and safety data along with less accessibility and higher cost of the drug. In the light of the above perspectives, ulipristal acetate although provides women and health-care providers with an effective alternative for emergency contraception extended up to 5 days post-unprotected intercourse or contraceptive failure, further long term evidence is warranted before a change in practice should be entertained.