The FDA has approved norelgestromin and ethinyl estradiol transdermal system (Ortho Evra, Ortho-McNeil Pharmaceuticals Inc, Raritan, NJ), a combination matrix-type patch, for prevention of pregnancy. The product releases 150 µg of norelgestromin and 20 µg of ethinyl estradiol to the bloodstream per 24 hours. Each patch is worn continuously for 1 week and then replaced with a new patch for a total of 3 weeks of patch wear. The fourth week is patch-free.
The approval was based on the results of three clinical trials, including two randomized trials with oral contraceptive comparators. A total of 3330 women used Ortho Evra for up to 1 year (13 cycles), for a total of 22 155 completed cycles. Pregnancy rates were approximately 1 per 100 person-years. One third of the pregnancies observed in the trials were in women who weighed at least 90 kg (198 lb), representing only 3% of the study population (JAMA. 2001;285:2347-2354).
Schwetz BA. New Contraceptive Patch. JAMA. 2002;287(5):578. doi:10.1001/jama.287.5.578-JFD20002-2-1