Pharmacokinetic overview of Ortho Evra™/Evra™

Abstract

Objective: The pharmacokinetics of norelgestromin, the primary active metabolite of norgestimate, plus ethinyl estradiol (EE), delivered by the once-weekly contraceptive patch (Ortho Evra™/Evra™), have been studied in eight trials. This overview summarizes the relevant pharmacokinetic data for the contraceptive patch. Design: Review article. Result(s): The amount of norelgestromin and EE absorbed from the patch is proportional to patch size: the 20-cm 2 patch (Ortho Evra™) delivers norelgestromin, 150 μg/d, and EE, 20 μg/d, to the systemic circulation. After single and multiple applications of the contraceptive patch, daily serum concentrations (area under the serum concentration-versus-time curve) of norelgestromin and EE were within the ranges generally seen with oral norgestimate, 250 μg/EE 35 μg (Ortho-Cyclen®/Cilest®), but without the peaks and troughs characteristic of oral dosing. Moreover, the contraceptive patch maintains serum concentrations of norelgestromin and EE within these ranges for up to 10 days, suggesting that clinical efficacy would be maintained even if a scheduled change is missed for as long as two full days. Regardless of the location of patch application (abdomen, buttock, upper outer arm, or torso [excluding breasts]) and even under conditions of heat, humidity, exercise, and cool-water immersion, efficacious concentrations of norelgestromin and EE are achieved. Coadministration of the patch with tetracycline did not affect the pharmacokinetics of norelgestromin and EE. Conclusion(s): The contraceptive patch exhibits an excellent pharmacokinetic profile, maintaining efficacious serum hormone concentrations under varying conditions.