Ortho Evra@ is the first birth control transdermal patch and contains a combination of
norelgestromin and ethinylestradiol. The patch can be applied to the buttocks, lower
abdomen, upper torso or arms; changed weekly for 3 weeks, followed by a patch-free
week. Norelgestromin is the active metabolite produced following oral administration of
norgestimate, the progestin component of the contraceptive, Ortho-Cyclen. The half-life
value of norelgestromin was approximately 28 h. Following application, norelgestromin
rapidly appeared in the serum, reached a plateau by approximately 48h and was
maintained at an approximate steady state throughout the wear period. Hepatic
metabolites of norelgestromin included norgestrel and various hydroxylated and conjugated metabolites that were eliminated by renal and fecal pathways. Ortho Evra
produced ovarian suppression and cycle control. It was significantly more effective in
suppressing follicular development than the leading oral contraceptive Triphasil (ethinyl
estradiol/levomorgestrel); was as effective in preventing pregnancies and had similar
tolerability profile. The patch offers 99% efficacy when used appropriately, as shown by
three clinical trials. However, a statistically significantly greater proportion of pregnancies
occurred among women weighing 90 kg or more. Ortho Evra was well tolerated, with
2.6% of women discontinuing treatment due to mild to moderate reactions at the site of
application. Thus, the patch combined the efficacy of oral contraceptives with the
convenience of just once-weekly dosing.
