Extended- and continuous-cycle oral contraceptives

Abstract

Five new oral contraceptives, classified as extended- or continuous-cycle oral contraceptives, have been approved by the United States Food and Drug Administration. These agents have various combinations of estrogen and progestin, and different effects on the length of women's menstrual cycles. Usually they shorten the duration of menses, decrease the frequency of menses to 4 times/year, or completely eliminate menses. These new oral contraceptives are given in the following regimens: 24 days followed by placebo for 4 days (24/4), 84 days followed by placebo for 7 days (84/7), or continuously (without placebo). These agents contain ethinyl estradiol 20 microg-drospirenone 3 mg (24/4); ethinyl estradiol 20 microg-norethindrone 1 mg (24/4); ethinyl estradiol 30 microg-levonorgestrel 150 microg (84/7); ethinyl estradiol 30 microg-levonorgestrel 150 microg (84/7) with very low-dose ethinyl estradiol (10 microg/day) for 7 days; and ethinyl estradiol 20 microg-levonorgestrel 90 microg continuously. Clinical trials have demonstrated that extended- and continuous-cycle oral contraceptives are as effective in preventing pregnancy as traditional oral contraceptives. These new agents also have similar adverse effects; however, the only significantly different adverse effect compared with traditional oral contraceptives in clinical trials was change in bleeding pattern. These oral contraceptives are associated with more breakthrough bleeding and spotting than the traditional pills. Long-term effects on efficacy and safety are not known, as these new products generally have been used for only 1-2 years. Extended- and continuous-cycle oral contraceptives are a new option for women desiring decreased menses or for whom decreased menses may alleviate symptoms of coexisting medical conditions.