It explains how the Committee for Medicinal Products for Human Use CHMP assessed the medicine to reach its opinion in favour of granting a marketing authorisation and its recommendations on the conditions of use for ellaOne. EllaOne is a medicine that contains the active substance ulipristal acetate. It is available as tablets 30 mg. EllaOne is a female emergency contraceptive to be taken within hours five days of unprotected sex or contraceptive failure such as a tear in a condom during sex.
EllaOne is taken as one tablet by mouth as soon as possible, but no later than hours, after unprotected sex or contraceptive failure. If the woman vomits within three hours of taking the medicine she should take another tablet. EllaOne can be taken at any time during the menstrual cycle. For pregnancy to occur there has to be ovulation release of eggs followed by the fertilisation of the egg fusion with a sperm and implantation in the womb.
The sex hormone progesterone plays a role in the timing of ovulation and in preparing the lining of womb to receive the fertilised egg. The active substance in ellaOne, ulipristal acetate, acts as a progesterone receptor modulator. This means that it attaches to the receptors that progesterone normally attaches to, preventing the hormone from having its effect. Through its actions on the progesterone receptors, ellaOne prevents pregnancies mainly by preventing or delaying ovulation.
If ovulation has already occurred, ellaOne is no longer effective. In one main study, ellaOne was given to 1, women aged on average 24 years who had requested emergency contraception between two and five days after unprotected sex or contraceptive failure. The main measure of effectiveness was the number of women who did not become pregnant. This number was then compared with the number of women who would have been expected to become pregnant if they had not taken a contraceptive.
This number was calculated from published pregnancy rates. An additional study compared ellaOne with levonorgestrel another medicine used in emergency contraception. This study included women who took the medicine within two days of unprotected sex or contraceptive failure. EllaOne was effective as an emergency contraceptive, reducing the number of unintended pregnancies.
