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In January 2012, we reported on a cohort study(1) conducted with the collaboration of the US Food and Drug Administration FDA; an elevated risk of venous thromboembolism (VTE) was calculated for the hormone patch EVRA (ethinyl estradiol [EE] + norelgestromin) and the vaginal ring NUVARING/CIRCLET (EE + etonogestrel). For the patch, the data supported evidence from previous studies. No such data had been previously reported for the vaginal ring (a-t 2012; 43: 15-6). A Danish cohort study (2) now confirms the safety concerns: All non-pregnant Danish women 15 to 49 years of age without previous cardiovascular or malignant disorders were included in the analysis. Compared to combined oral contraceptives with the progestogen levonorgestrel (e.g. MICROGYNON; 231,675 women-years, 144 VTE), the transdermal contraceptive and the intravaginal contraceptive double the risk of VTE (hormone patch: Rate Ratio [RR] 2.31; 95% confidence interval [CI] 1.02-5.23; vaginal ring: RR 1.90; 95% CI 1.33-2.71). Particularly the patch is used relatively rarely in Denmark, however, so that the study only included 6,178 women-years, with six confirmed events (vaginal ring: 50,334 women-years, 39 VTE) (2). These are the first data on the VTE risk associated with the European hormone patch, which contains 20% less estrogen in its depot than the US product used in previous studies. Since both are bioequivalent, we had already expected comparable safety concerns. Among combined hormonal contraceptives, well-tried second generation pills with levonorgestrel are the drug of choice, - Ed.
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