2023
The effect of rifampin on serum etonogestrel concentrations and biomarkers of ovulation among contraceptive implant users: A pharmacokinetic and pharmacodynamic study
Lazorwitz A, Sheeder J, Teal S. The effect of rifampin on serum etonogestrel concentrations and biomarkers of ovulation among contraceptive implant users: A pharmacokinetic and pharmacodynamic study. Contraception 2023, 123: 110035. PMID: 36997081, PMCID: PMC10461170, DOI: 10.1016/j.contraception.2023.110035.Peer-Reviewed Original ResearchConceptsContraceptive implant usersSerum etonogestrel concentrationsStrong CYP3A inducersENG implant usersEtonogestrel concentrationsMedian ageImplant usersCYP3A inducersP4 concentrationsMedian body mass indexSerum E2 concentrationsBody mass indexSignificant decreaseParticipants' median ageSuppression of ovulationSerum P4 concentrationsEffect of rifampinDrug-drug interactionsLiquid chromatography-mass spectrometry assayOnly short exposuresWilcoxon signed-rank testBaseline E2Rifampin 600Rifampin exposureRifampin therapy
2022
P079Etonogestrel contraceptive implant users can experience breakthrough ovulation with only two weeks of exposure to a strong cyp3a inducer
Lazorwitz A, Teal S, Sheeder J. P079Etonogestrel contraceptive implant users can experience breakthrough ovulation with only two weeks of exposure to a strong cyp3a inducer. Contraception 2022, 116: 92. DOI: 10.1016/j.contraception.2022.09.103.Peer-Reviewed Original ResearchStrong CYP3A inducersBreakthrough ovulationCYP3A inducersE2 concentrationsP4 concentrationsMedian ageOvulation suppressionImplant usersPg/Baseline serum concentrationsContraceptive implant usersEtonogestrel implant usersSerum E2 concentrationsParticipants' median ageSerum P4 concentrationsENG implant usersDrug-drug interactionsRifampin exposureMedian durationENG implantMedian BMIEndogenous estradiolSerum concentrationsSurrogate biomarkerWeeks of exposure