Research Studies

This study aims to validate prior pharmacokinetic research with combined oral contraceptive pill (COCP) users that supports utilizing a 24-hour trough concentration as an accurate proxy for the intensive pharmacokinetic parameter of area under the curve (gold standard pharmacokinetics). COCP users have wide variability in their serum drug concentrations (pharmacokinetics) even among individuals taking the same exact formulation of COCP. As we are developing a research endeavor to explore the pharmacogenomics of hormonal contraception, we plan to eventually broaden our research in this field to COCP users, and thus need a reliable, yet cost-effective means to determine an individual's COCP pharmacokinetic profile. Published literature has found that the 24 hour trough concentration measurement at steady state is a reliable and highly correlated pharmacokinetic measurement compared to the standard intensive area under the curve measurements. However, these prior studies were all conducted with COCPs containing levonorgestrel, a 2nd generation progestin with high androgenicity. This study will duplicate the pharmacokinetic methodology of the prior published study with a COCP containing desogestrel, a third generation progestin with low androgenicity. We will recruit 20 healthy, reproductive-age females and have them take a standard pack of desogestrel-containing COCPs (21 active days). Participants will then undergo intensive pharmacokinetic measurements (12 total measures) on day 21 of the pill pack to calculate a standard area under the curve and 24 trough concentration. We will then determine the correlation between these pharmacokinetic measurements for both etonogestrel (the active metabolite of desogestrel) and ethinyl estradiol to validate that the 24 hour trough concentration remains an appropriate surrogate pharmacokinetic measurement for this type of COCP. This research will directly inform our planned large pharmacogenomic study with COCP users and hopefully support the need for only a single pharmacokinetic measurement.