Ethinylestradiol + etonogestrel contraceptive vaginal ring: new drug. Possibly useful in some situations

(1) The standard hormonal contraception consists of a combined oral contraceptive containing about 30 micrograms of ethinylestradiol and a well-evaluated and widely used progestin such as levonorgestrel or norethisterone. (2) A vaginal ring delivering about 120 micrograms of etonogestrel and 15 micrograms of ethinylestradiol daily for 3 consecutive weeks per cycle, which is then removed for one week, is now marketed in France as a contraceptive. Etonogestrel, a desogestrel metabolite, is classified as a 'third-generation' progestin. (3) On the basis of 2 non-comparative trials involving a total of 2322 women, the vaginal ring's contraceptive efficacy, as measured by the Pearl index, is about 1 per 100 woman-years, a value similar to that of other available combined hormonal contraceptives. (4) In total, 41% and 29.6% of women withdrew early from each of the two trials. In the two trials combined, 15.6% of women withdrew due to adverse events. (5) A comparative trial versus oral ethinylestradiol + levonorgestrel showed no difference in adherence rates, and similar Pearl index scores. (6) The most frequent adverse effects, occurring in about 20% of women using the vaginal ring, were gynecological disorders (vaginitis, leukorrhea or local discomfort). The other adverse effects were those common to all hormonal contraceptives. (7) The thromboembolic risk of etonogestrel, when administered in a contraceptive ring, has not been evaluated. (8) In practice, the standard hormonal contraceptive remains a combined oral contraceptive containing about 30 micrograms of ethinylestradiol plus a well-evaluated progestin such as levonorgestrel or norethisterone. The vaginal ring offers no advantage in terms of efficacy, adverse effects or adherence. However, it is an additional effective contraceptive and may be preferred by some women, at least temporarily, in certain situations.