Pharmacokinetics and pharmacodynamics of a transdermal contraceptive patch and an oral contraceptive

This open-label, randomized, 2-way crossover study characterized the pharmacokinetics and pharmacodynamics of a transdermal contraceptive patch and a norgestimate-containing oral contraceptive. Healthy women (n = 34) applied a patch once weekly for 3 consecutive weeks during each of 2 cycles and received an oral contraceptive for 21 consecutive days during each of 2 cycles. Plasma concentrations of norelgestromin and ethinyl estradiol peaked and waned after daily oral contraceptive administration, whereas they rose and reached steady-state levels after first patch application. Norelgestromin exposure was similar; ethinyl estradiol exposure was higher for the patch than oral contraceptive. Hepatic estrogenic activity, assessed by hepatic globulin synthesis, was similar for corticosteroid-binding globulin and corticosteroid-binding globulin-binding capacity and higher for sex hormone-binding globulin for the patch versus oral contraceptive. The clinical significance of the differences in pharmacokinetic and pharmacodynamic profiles between the patch and oral contraceptive is not fully known. No serious adverse events or discontinuations due to adverse events were recorded.