Low-dose ethinylestradiol/levonorgestrel.

Low-dose ethinylestradiol/levonorgestrel 20 microg/100 microg is a combined oral contraceptive that prevents pregnancy primarily by inhibiting ovulation. The Pearl index (pregnancies per 100 woman-years of use) with ethinylestradiol/levonorgestrel 20 microg/100 microg was 0.88 and the cumulative pregnancy rate was 1.9% at the end of a 3-year open-label trial (1708 women with 26 554 evaluable cycles). The contraceptive efficacy of ethinylestradiol/levonorgestrel 20 microg/100 microg was similar to that of other low-dose combined oral contraceptives containing ethinylestradiol 20 or 35 microg in a 6-cycle trial (463 evaluable women). Ethinylestradiol/levonorgestrel 20 microg/100 microg is well tolerated; adverse events were those commonly associated with combined oral contraceptives. Headache and metrorrhagia (2% of women) were the most common adverse events leading to treatment discontinuation in the 3-year trial. Cycle control in open-label trials in women receiving up to 36 cycles of ethinylestradiol/levonorgestrel 20 microg/100 microg was generally good, with the incidence of intermenstrual bleeding being highest during the first few cycles of use and decreasing thereafter.