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A drug-drug interaction (DDI) study was conducted to evaluate the effect of icenticaftor (QBW251) on the pharmacokinetics (PK) of a 5-probe cytochrome P450 (CYP) substrate cocktail, guided by in vitro studies in human hepatocytes and liver microsomes. Another DDI study investigated the effect of icenticaftor on the PK and pharmacodynamics (PD) of a monophasic oral contraceptive (OC) containing ethinyl estradiol (EE) and levonorgestrel (LVG) in premenopausal healthy female subjects. The static-mechanistic DDI assessment indicated that icenticaftor may moderately induce the metabolic clearance of co-medications metabolized by CYP3A4 (area under the concentration-time curve [AUC] ratio: 0.47) and potentially CYP2C; icenticaftor may also weakly inhibit the metabolic clearance of co-medications metabolized by CYP1A2 and CYP3A4 (AUC ratio: 1.35 and 1.86, respectively) and moderately inhibit CYP2B6 (AUC ratio: 2.11). In the CYP substrate cocktail DDI study, icenticaftor 300 mg twice daily (b.i.d.) moderately inhibited CYP1A2 (AUC ratio: 3.35) and CYP2C19 (AUC ratio: 2.70). As expected from the results of the in vitro studies, weak induction was observed for CYP3A4 (AUC ratio: 0.51) and CYP2C8 (AUC ratio: 0.66). In the OC DDI study, co-administration of icenticaftor 450 mg b.i.d. with monophasic OC containing 30-μg EE and 150-μg LVG once daily reduced the plasma exposure of both components by approximately 50% and led to increased levels of follicle-stimulating hormone and luteinizing hormone. These results provide valuable guidance for the use of icenticaftor in patients taking concomitant medications that are substrates of CYP enzymes or patients using OCs., (© 2024 The Author(s). Clinical and Translational Science published by Wiley Periodicals LLC on behalf of American Society for Clinical Pharmacology and Therapeutics.)

The endothelin A receptor antagonist zibotentan, combined with the sodium-glucose co-transporter-2 inhibitor dapagliflozin, is being investigated for the treatment of chronic kidney disease with high proteinuria. To allow women of childbearing potential access to this treatment, highly effective contraception is required and drug interactions compromising contraception reliability must be avoided. This study investigated the risk of pharmacokinetic (PK) interaction between zibotentan and the contraceptives ethinyl estradiol and levonorgestrel. A single-sequence, within-participant comparison study was conducted in 24 healthy women of non-childbearing potential, comparing the PK of ethinyl estradiol/levonorgestrel alone and with zibotentan. Single oral doses of 0.06 mg ethinyl estradiol/0.3 mg levonorgestrel were administered on Days 1 and 15; zibotentan 10 mg was dosed orally, once-daily through Days 6-19. PK profiles were determined and ethinyl estradiol/levonorgestrel PK was compared between Day 1 and 15 based on geometric least-squares mean ratios of PK parameters, including maximum observed concentration (C max ) and area under the plasma concentration-time curve from zero to infinity (AUC inf ). Co-administration with zibotentan did not affect ethinyl estradiol PK (geometric mean ratio [90% confidence interval] C max 1.05 [0.99-1.11], AUC inf 1.00 [0.96-1.05]), while a weak interaction (increased exposure) was observed for levonorgestrel (C max 1.12 [1.02-1.23], AUC inf 1.30 [1.21-1.39]), which was regarded as without clinical relevance. Plasma exposure of ethinyl estradiol/levonorgestrel was not reduced by multiple-dose zibotentan. In conclusion, contraception containing ethinyl estradiol/levonorgestrel is regarded possible under zibotentan-containing treatments. This expands choices for women of childbearing potential, supporting diversity in the ZENITH High Proteinuria trial., (© 2024 The Authors. Clinical Pharmacology & Therapeutics published by Wiley Periodicals LLC on behalf of American Society for Clinical Pharmacology and Therapeutics.)

Background: Vaginal rings formulated to deliver two drugs simultaneously have potential as user-controlled, long-acting methods for dual prevention of HIV and pregnancy., Methods: Two phase 1 randomized trials (MTN-030/IPM 041 and MTN-044/IPM 053/CCN019) respectively enrolled 24 and 25 healthy, HIV-negative participants to evaluate safety, pharmacokinetics, and vaginal bleeding associated with use of a vaginal ring containing 200mg dapivirine (DPV) and 320mg levonorgestrel (LNG) designed for 90-day use. MTN-030/IPM 041 compared the DPV/LNG ring to a DPV-only ring (200mg) over 14 days of use. MTN-044/IPM 053/CCN019 compared continuous or cyclic use of the DPV/LNG ring over 90 days of use. Safety was assessed by recording adverse events (AEs). DPV and LNG concentrations were quantified in plasma, cervicovaginal fluid, and cervical tissue. Vaginal bleeding was self-reported., Results: There were no differences in the proportion of participants with grade ≥2 genitourinary AEs or grade ≥3 AEs with DPV/LNG ring vs. DPV ring use (p = .22), or with DPV/LNG ring continuous vs. cyclic use (p = .67). Higher plasma DPV concentrations were observed in users of DPV/LNG compared to DPV-only rings (Cmax p = 0.049; AUC p = 0.091). Plasma DPV and LNG concentrations were comparable with continuous and cyclic use (Cmax p = 0.74; AUC p = 0.25). With cyclic use, median nadir plasma DPV concentration was approximately 300 pg/mL two days after removal and median t1/2 for cervicovaginal fluid DPV concentration was 5.76 hours (n = 3). Overall bleeding experiences did not differ between continuous and cyclic users (p = 0.12)., Conclusions: The extended duration DPV/ LNG rings were well tolerated and the observed DPV concentrations in plasma and cervicovaginal fluid when used continuously exceeded concentrations observed in previous DPV ring efficacy studies. LNG concentrations in plasma were comparable with other efficacious LNG-based contraceptives. Genital DPV concentrations had a short half-life and were thus not well sustained following ring removal., Competing Interests: The following authors have read the journal’s policy and have competing interests: Sharon L. Achilles has received consulting fees from Mayne Pharma and Merck and has received research funding from The National Institutes of Health, the US Food and Drug Administration, the Pennsylvania Department of Health, Society of Family Planning Research Fund, Estetra SRL (an affiliate company of Mithra Pharmaceuticals), EvoFem, and Merck, all of which were managed by Magee-Womens Research Institute. Barbra A. Richardson has received payment from Gilead Sciences for DSMB membership. Brid Devlin and John Steytler were full-time salaried employees of the International Partnership for Microbicides (IPM), a non-profit company registered in the United States of America, at the time the work was performed. Craig W. Hendrix is an Inventor on patent relating to vaginal microbicides and the founder of a microbicide development company, both unrelated to this study product and both managed by Johns Hopkins University. Beatrice A. Chen has served on a Merck & Co. advisory board and has received research grants from Sebela, Mylan, and Medicines360, all of which were managed by Magee-Womens Research Institute. NIH employees (Diana L. Blithe, Jill Brown, and Jeanna M. Piper) contributed to the study design, manuscript development and the decision to publish as well as providing safety oversight during study conduct but had no role in data collection and analysis. All other authors have declared that no competing interests exist. This does not alter our adherence to PLOS One policies on sharing data and materials., (Copyright: This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.)

The wide array of polydimethylsiloxane (PDMS) variants available on the market, coupled with the intricate combination of additives in silicone polymers, and the incomplete understanding of drug release behavior make formulation development of levonorgestrel intrauterine systems (LNG-IUSs) formidable. Accordingly, the objectives of this work were to investigate the impact of excipients on formulation attributes and in vitro performance of LNG-IUSs, elucidate drug release mechanisms, and thereby improve product understanding. LNG-IUSs with a wide range of additives and fillers were prepared, and in vitro drug release testing was conducted for up to 12 months. Incorporating various additives and/or fillers (silica, silicone resins, silicone oil, PEG, etc.) altered the crystallization kinetics of the crosslinked polymer, the viscosity, and the microstructure. In addition, drug-excipient interactions can occur. Interestingly, additives which increased matrix hydrophobicity and hindered PDMS crystallization facilitated dissolution and permeation of the lipophilic LNG. The influence of additives and lubricants on the mechanical properties of LNG-IUSs were also evaluated. PDMS chemical substitution and molecular weight were deemed to be most critical polymer attributes to the in vitro performance of LNG-IUSs. Drugs with varying physicochemical characteristics were used to prepare IUSs, modeling of the release kinetics was performed, and correlations between release properties and the various physicochemical attributes of the model drugs were established. Strong correlations between first order release rate constants and both drug solubility and Log P underpin the partition and diffusion-based release mechanisms in LNG-IUSs. This is the first comprehensive report to provide a mechanistic understanding of material-property-performance relationships for IUSs. This work offers an evidence-based approach to rational excipient selection and tailoring of drug release to achieve target daily release rates in vivo. The novel insights gained through this research could be helpful for supporting development of brand and generic IUS products as well as their regulatory assessment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

This parallel-arm, phase I study investigated the potential cytochrome P450 (CYP)3A induction effect of NBI-1065845 (TAK-653), an investigational α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor potentiator in phase II development for major depressive disorder. The midazolam treatment arm received the sensitive CYP3A substrate midazolam on Day 1, followed by NBI-1065845 alone on Days 5-13; on Day 14, NBI-1065845 was administered with midazolam, then NBI-1065845 alone on Day 15. The oral contraceptive treatment arm received ethinyl estradiol-levonorgestrel on Day 1, then NBI-1065845 alone on Days 5-13; on Day 14, NBI-1065845 was administered with ethinyl estradiol-levonorgestrel, then NBI-1065845 alone on Days 15-17. Blood samples were collected for pharmacokinetic analyses. The midazolam treatment arm comprised 14 men and 4 women, of whom 16 completed the study. Sixteen of the 17 healthy women completed the oral contraceptive treatment arm. After multiple daily doses of NBI-1065845, the geometric mean ratios (GMRs) (90% confidence interval) for maximum observed concentration were: midazolam, 0.94 (0.79-1.13); ethinyl estradiol, 1.00 (0.87-1.15); and levonorgestrel, 0.99 (0.87-1.13). For area under the plasma concentration-time curve (AUC) from time 0 to infinity, the GMRs were as follows: midazolam, 0.88 (0.78-0.98); and ethinyl estradiol, 1.01 (0.88-1.15). For levonorgestrel, the GMR for AUC from time 0 to the last quantifiable concentration was 0.87 (0.78-0.96). These findings indicate that NBI-1065845 is not a CYP3A inducer and support its administration with CYP3A substrates. NBI-1065845 was generally well tolerated, with no new safety signals observed after coadministration of midazolam, ethinyl estradiol, or levonorgestrel., (© 2024 The Authors. Clinical and Translational Science published by Wiley Periodicals LLC on behalf of American Society for Clinical Pharmacology and Therapeutics.)

Background and Objective: Abrocitinib is an oral small-molecule Janus kinase (JAK)-1 inhibitor approved for the treatment of moderate-to-severe atopic dermatitis. In vitro studies indicated that abrocitinib is a weak time-dependent inhibitor of cytochrome P450 (CYP) 2C19/3A and a weak inducer of CYP1A2/2B6/2C19/3A. To assess the potential effect of abrocitinib on concomitant medications, drug-drug interaction (DDI) studies were conducted for abrocitinib with sensitive probe substrates of these CYP enzymes. The impact of abrocitinib on hormonal oral contraceptives (ethinyl estradiol and levonorgestrel), as substrates of CYP3A and important concomitant medications for female patients, was also evaluated., Methods: Three Phase 1 DDI studies were performed to assess the impact of abrocitinib 200 mg once daily (QD) on the probe substrates of: (1) 1A2 (caffeine), 2B6 (efavirenz) and 2C19 (omeprazole) in a cocktail study; (2) 3A (midazolam); and (3) 3A (oral contraceptives)., Results: After multiple doses of abrocitinib 200 mg QD, there is a lack of effect on the pharmacokinetics of midazolam, efavirenz and contraceptives. Abrocitinib increased the area under the concentration time curve from 0 to infinity (AUC inf ) and the maximum concentration (C max ) of omeprazole by approximately 189 and 134%, respectively. Abrocitinib increased the AUC inf of caffeine by 40% with lack of effect on C max ., Conclusions: Based on the study results, abrocitinib is a moderate inhibitor of CYP2C19. Caution should be exercised when using abrocitinib concomitantly with narrow therapeutic index medicines that are primarily metabolized by CYP2C19 enzyme. Abrocitinib is a mild inhibitor of CYP1A2; however, the impact is not clinically relevant, and no general dose adjustment is recommended for CYP1A2 substrates. Abrocitinib does not inhibit CYP3A or induce CYP1A2/2B6/2C19/3A and does not affect the pharmacokinetics of contraceptives., Clinical Trials Registration: ClinicalTrials.gov registration IDs: NCT03647670, NCT05067439, NCT03662516., (© 2024. The Author(s).)

Purpose: Midostaurin, approved for treating FLT-3-mutated acute myeloid leukemia and advanced systemic mastocytosis, is metabolized by cytochrome P450 (CYP) 3A4 to two major metabolites, and may inhibit and/or induce CYP3A, CYP2B6, and CYP2C8. Two studies investigated the impact of midostaurin on CYP substrate drugs and oral contraceptives in healthy participants., Methods: Using sentinel dosing for participants' safety, the effects of midostaurin at steady state following 25-day (Study 1) or 24-day (Study 2) dosing with 50 mg twice daily were evaluated on CYP substrates, midazolam (CYP3A4), bupropion (CYP2B6), and pioglitazone (CYP2C8) in Study 1; and monophasic oral contraceptives (containing ethinylestradiol [EES] and levonorgestrel [LVG]) in Study 2., Results: In Study 1, midostaurin resulted in a 10% increase in midazolam peak plasma concentrations (C max ), and 3-4% decrease in total exposures (AUC). Bupropion showed a 55% decrease in C max and 48-49% decrease in AUCs. Pioglitazone showed a 10% decrease in C max and 6% decrease in AUC. In Study 2, midostaurin resulted in a 26% increase in C max and 7-10% increase in AUC of EES; and a 19% increase in C max and 29-42% increase in AUC of LVG. Midostaurin 50 mg twice daily for 28 days ensured that steady-state concentrations of midostaurin and the active metabolites were achieved by the time of CYP substrate drugs or oral contraceptive dosing. No safety concerns were reported., Conclusion: Midostaurin neither inhibits nor induces CYP3A4 and CYP2C8, and weakly induces CYP2B6. Midostaurin at steady state has no clinically relevant PK interaction on hormonal contraceptives. All treatments were well tolerated., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Pharmacokinetic data are lacking for progestin-releasing subdermal contraceptive implants when used with either rilpivirine- or darunavir/ritonavir-based ART., Objectives: To characterize the pharmacokinetics of etonogestrel or levonorgestrel implants when administered with these ART regimens over 48 weeks., Patients and Methods: Two separate, parallel, three-group, non-randomized, pharmacokinetic studies evaluated either etonogestrel or levonorgestrel in women receiving rilpivirine- or darunavir-based ART compared with women without HIV (control group). Participants on ART were switched to rilpivirine-based ART with a run-in period of 6 weeks or darunavir-based ART with a run-in of 2 weeks prior to implant insertion. Plasma was collected on Day 0, and 1, 4, 12, 24, 36 and 48 weeks post-insertion. Plasma progestin concentrations were compared between ART and control groups by geometric mean ratio (GMR) and 90% CI., Results: At the primary endpoint of Week 24, progestin concentrations were similar between the rilpivirine and control groups [etonogestrel: 1.18 (0.99-1.37); levonorgestrel: 1.16 (0.97-1.33)]. At Week 24, progestin exposure was higher in the darunavir groups compared with the control group [etonogestrel: 2.56 (1.69-3.28); levonorgestrel: 1.89 (1.38-2.29)]. Results remained consistent through to Week 48. No differences in etonogestrel-related adverse events were observed, but both ART groups experienced more menstrual abnormalities versus the control group with levonorgestrel., Conclusions: Etonogestrel and levonorgestrel concentrations were not altered by rilpivirine-based ART. Although progestin concentrations were higher in the ART groups containing ritonavir-boosted darunavir, no implant-related serious adverse events were observed. Both progestin-releasing implants are an appropriate contraceptive option with either rilpivirine- or darunavir/ritonavir-based ART., (© The Author(s) 2022. Published by Oxford University Press on behalf of British Society for Antimicrobial Chemotherapy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: Contraceptive implants containing etonogestrel and levonorgestrel have emerged as popular contraceptive options among women in areas of high HIV burden in sub-Saharan Africa. However, recent pharmacokinetic data have shown drug-drug interactions between implants and efavirenz-containing antiretroviral therapy (ART), reducing the effectiveness of the implants. Here, we evaluated pregnancy incidence in 6-month intervals following implant initiation among women using efavirenz and contraceptive implants to assess whether the risk of breakthrough pregnancy is higher after specific periods of implant use., Methods: We used data from a retrospective longitudinal analysis of women living with HIV ages 18-45 years in western Kenya who attended HIV-care facilities between 2011 and 2015. We used Cox proportional hazard models to compute hazard ratios (HRs) for breakthrough pregnancy by implant type and ART regimen. Depending on the model, we adjusted for socio-demographic and clinical factors, programme, site and interaction between calendar time and ART regimen. We utilized inverse probability weights (IPWs) to account for three sampling phases (electronic medical record [EMR], chart review and phone interview) and calculated overall parameter estimates., Results: Women contributed 14,768 woman-years from the largest sampling phase (EMR). The median age was 31 years. Women used etonogestrel implants for 26-69% of the time and levonorgestrel implants for 7-31% of the time, depending on the sampling phase. Women used efavirenz, nevirapine or no ART for 27-33%, 40-46% and 15-26% of follow-ups, respectively. When combining sampling phases, there was little evidence to suggest that the relative hazard of pregnancy among efavirenz-containing ART users relative to nevirapine-containing ART changed with length of time on implants: IPW-adjusted HR of 3.1 (CI: [1.5; 6.4]) at 12 months, 3.4 (CI: [1.8; 6.3]) at 24 months, 3.8 (CI: [1.9; 7.7]) at 36 months and 4.2 (CI: [1.6; 11.1]) at 48 months (interaction p-value = 0.88). Similarly, no significant change in HRs over time was found when comparing women not using ART to nevirapine-containing ART users (interaction p-value = 0.49)., Conclusions: We did not find evidence to suggest implants being more fallible from drug-drug interactions with efavirenz at later time intervals of implant use. Thus, we would not recommend shortening the duration of implant use or replacing implants sooner when concomitantly used with efavirenz., (© 2022 The Authors. Journal of the International AIDS Society published by John Wiley & Sons Ltd on behalf of the International AIDS Society.)

An intrauterine system (IUS) can be implanted in the uterus and deliver drug directly at the site of pharmacological action. Mirena was the first FDA-approved levonorgestrel (LNG) releasing IUS without an approved generic form. Its 5-year application duration presents challenges for bioequivalence (BE) assessment using the conventional in vivo studies with pharmacokinetic and/or comparative clinical endpoints. Conventionally, along with other conditions, BE could be established if the 90% confidence interval (CI) of the ratio of geometric means of residual LNG at the end of 5 years is within the BE limits of 80.00% and 125.00%. Modeling and simulation were conducted to identify a shortened BE study duration and its corresponding BE acceptance limit that can be used as a surrogate for the conventional limit for a 5-year study. Simulation results suggest that having the 90% CI of the residual LNG 12 months post insertion within 95.00-105.26% would ensure that residual LNG amount at 5 years to be within 80.00-125.00%. This modeling and simulation practice leads to the current BE recommendation: if a test IUS is made of the same material in the same concentration and has the same physical dimensions as the Mirena, its BE could be established by showing (1) comparative physicochemical and mechanical properties; (2) comparative in vitro drug release behavior for 5 years; and (3) performance in a comparative short-term in vivo study and BE based on 90% confidence interval of test and reference ratio of residual LNG to be within 95.00-105.26% at month 12., (© 2022. This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply.)

Microneedle (MN)-based technologies have been proposed as a means to facilitate minimally invasive sustained delivery of long-acting hormonal contraceptives into the skin. Intradermal administration is a new route of delivery for these contraceptives and therefore no established laboratory methods or experimental models are available to predict dermal drug release and pharmacokinetics from candidate MN formulations. This study evaluates an in vitro release (IVR) medium and a medium supplemented with ex vivo human skin homogenate (SH) as potential laboratory models to investigate the dermal release characteristics of one such hormonal contraceptive that is being tested for MN delivery, levonorgestrel (LNG), and provides details of an accompanying novel two-step liquid-liquid drug extraction procedure and sensitive reversed-phase HPLC-UV assay. The extraction efficiency of LNG was 91.7 ± 3.06% from IVR medium and 84.6 ± 1.6% from the medium supplemented with SH. The HPLC-UV methodology had a limit of quantification of 0.005 µg/mL and linearity between 0.005 and 25 µg/mL. Extraction and detection methods for LNG were exemplified in both models using the well-characterised, commercially available sustained-release implant (Jadelle®). Sustained LNG release from the implant was detected in both media over 28 days. This study reports for the first time the use of biologically relevant release models and a rapid, reliable and sensitive methodology to determine release characteristics of LNG from intradermally administered long-acting drug delivery systems., (© 2021. The Author(s).)

Combined oral contraceptive pills are the most commonly used hormonal contraceptives for the prevention of unintended pregnancies in United States. They consist of a progestin (e.g., levonorgestrel (LNG)) and an estrogen component, typically ethinyl estradiol (EE). In addition to adherence issues, drug-drug interactions (DDIs) and obesity (women with body mass index (BMI) ≥ 30 kg/m 2 ) are prime suspects for decreased LNG efficacy. Therefore, we developed an integrated physiologically-based pharmacokinetic modeling and model-based meta-analysis approach to determine LNG's efficacy threshold concentrations and to evaluate the impact of DDIs and obesity on the efficacy of LNG-containing hormonal contraceptives (HCs). Based on this approach, co-administration of strong CYP3A4 inducers and LNG-containing HCs (LNG150: LNG 150 µg + EE 30 µg and LNG100: LNG 100 µg + EE 20 µg) resulted in a predicted clinically relevant decrease of LNG plasma exposure (women with BMI < 25 kg/m 2 : 50-65%; obese women: 70-75%). Following administration of LNG150 or LNG100 in the presence of a CYP3A4 inducer, there was an increase in mean Pearl Index of 1.2-1.30 and 1.80-2.10, respectively, in women with BMI < 25 kg/m 2 (incidence rate ratios (IRRs): 1.7-2.2), whereas it ranged from 1.6-1.80 and 2.40-2.85 in obese women (IRR: 2.2-3.0), respectively. Our results suggest that the use of backup or alternate methods of contraception is not necessarily required for oral LNG + EE formulations except within circumstances of both obesity and strong CYP3A4 inducer concomitance following administration of LNG100., (© 2021 The Authors. Clinical Pharmacology & Therapeutics © 2021 American Society for Clinical Pharmacology and Therapeutics.)

Background and Objectives: Nintedanib is a tyrosine kinase inhibitor approved for the treatment of systemic sclerosis-associated interstitial lung disease (SSc-ILD), idiopathic pulmonary fibrosis, and other chronic fibrosing ILDs with a progressive phenotype. As nintedanib may cause foetal harm, patients taking nintedanib should avoid pregnancy. The objective of this study was to investigate the effect of nintedanib co-administration on the pharmacokinetics of Microgynon (ethinylestradiol and levonorgestrel) in female patients with SSc-ILD., Methods: This was an open-label, two-period, fixed-sequence, drug-drug interaction study. Female patients with SSc and ≥ 10% extent of fibrotic ILD on a high-resolution computed tomography scan were eligible to participate. In Period 1, patients received one Microgynon tablet (ethinylestradiol 30 μg and levonorgestrel 150 μg) ≥ 3 days before the first administration of nintedanib in Period 2. In Period 2, patients received one Microgynon tablet following intake of nintedanib 150 mg twice daily for ≥ 10 consecutive days. The primary pharmacokinetic endpoints were the areas under the plasma concentration-time curve of ethinylestradiol and levonorgestrel over the time interval from 0 to the last quantifiable data point (AUC 0-tz ) and the maximum measured concentrations of ethinylestradiol and levonorgestrel in plasma (C max ). The secondary pharmacokinetic endpoint was the area under the plasma concentration-time curve of ethinylestradiol and levonorgestrel over the time interval from 0 extrapolated to infinity (AUC 0-∞ ). The relative exposures of ethinylestradiol and levonorgestrel when administered alone and in combination with nintedanib were assessed using an ANOVA model., Results: Seventeen patients were treated. Pharmacokinetic data from 15 patients were analysed. Plasma concentration-time profiles of ethinylestradiol and levonorgestrel were similar following administration of Microgynon before and after administration of nintedanib for ≥ 10 consecutive days. Adjusted geometric mean (gMean) ratios [90% confidence intervals (CIs)] for AUC 0‒tz (101.4% [92.8, 110.7]) and AUC 0‒∞ (101.2% [94.0, 109.1]) indicated that there was no difference in total ethinylestradiol exposure when Microgynon was administered before or after administration of nintedanib. The adjusted gMean ratio for C max of ethinylestradiol (116.7% [90% CI 107.6, 126.5]) indicated an increase in peak exposure in the presence of nintedanib. Adjusted gMean ratios [90% CIs] for AUC 0-tz (96.4% [91.5, 101.6]) and C max (100.9% [89.9, 113.2]) indicated that there was no difference in total or peak levonorgestrel exposure when Microgynon was administered before or after administration of nintedanib. The adjusted gMean ratio for AUC 0‒∞ of levonorgestrel indicated a decrease in total exposure in the presence of nintedanib (88.1% [90% CI 80.0, 97.0])., Conclusion: Pharmacokinetic data indicate that there is no relevant effect of nintedanib on plasma exposure to ethinylestradiol and levonorgestrel in female patients with SSc-ILD., Trial Registration: Clinicaltrials.gov NCT03675581., (© 2021. The Author(s).)

Purpose: This study aimed at evaluating the effect of rucaparib on the pharmacokinetics of rosuvastatin and oral contraceptives in patients with advanced solid tumors and the safety of rucaparib with and without coadministration of rosuvastatin or oral contraceptives., Methods: Patients received single doses of oral rosuvastatin 20 mg (Arm A) or oral contraceptives ethinylestradiol 30 µg + levonorgestrel 150 µg (Arm B) on days 1 and 19 and continuous doses of rucaparib 600 mg BID from day 5 to 23. Serial blood samples were collected with and without rucaparib for pharmacokinetic analysis., Results: Thirty-six patients (n = 18 each arm) were enrolled and received at least 1 dose of study drug. In the drug-drug interaction analysis (n = 15 each arm), the geometric mean ratio (GMR) of maximum concentration (C max ) with and without rucaparib was 1.29 for rosuvastatin, 1.09 for ethinylestradiol, and 1.19 for levonorgestrel. GMR of area under the concentration-time curve from time zero to last quantifiable measurement (AUC 0-last ) was 1.34 for rosuvastatin, 1.43 for ethinylestradiol, and 1.56 for levonorgestrel. There was no increase in frequency of treatment-emergent adverse events (TEAEs) when rucaparib was given with either of the probe drugs. In both arms, most TEAEs were mild in severity and considered unrelated to study treatment., Conclusion: Rucaparib 600 mg BID weakly increased the plasma exposure to rosuvastatin or oral contraceptives. Rucaparib safety profile when coadministered with rosuvastatin or oral contraceptives was consistent with that of rucaparib monotherapy. Dose adjustments of rosuvastatin and oral contraceptives are not necessary when coadministered with rucaparib. ClinicalTrials.gov NCT03954366; Date of registration May 17, 2019., (© 2021. The Author(s).)

Filgotinib (FIL) is a potent and selective JAK1 inhibitor in clinical development for treatment of severe inflammatory diseases. A drug-drug interaction study to evaluate the potential effect of FIL on the pharmacokinetics (PK) of the oral contraceptive levonorgestrel (LEVO)/ethinyl estradiol (EE) was conducted. This was a phase 1, open-label, randomized, crossover study in healthy female subjects (N = 24). Subjects received a single dose of LEVO (150 μg)/EE (30 μg) alone (reference), or in combination with multiple-dose FIL (200 mg once daily for 15 days; test). Intensive PK sampling was conducted, and safety was assessed throughout the study. PK interactions were evaluated using 90% confidence intervals of the geometric least squares mean ratios of the test versus reference treatments. All 24 subjects enrolled completed study treatments. Coadministration of FIL with the oral contraceptive did not alter the PK of LEVO and EE; the 90% confidence intervals of the geometric least squares mean ratios were contained within bioequivalence bounds (80%-125%). Exposures of FIL were consistent with observed clinical exposure data. Study treatments were generally well tolerated. All adverse events were mild. Coadministration with FIL did not alter the PK of LEVO/EE, and hormonal contraceptives can serve as an effective contraception method for subjects on FIL treatment., (© 2020, The American College of Clinical Pharmacology.)

Levonorgestrel (LNG) is the active moiety in many hormonal contraceptive formulations. It is typically coformulated with ethinyl estradiol (EE) to decrease intermenstrual bleeding. Due to its widespread use and CYP3A4-mediated metabolism, there is concern regarding drug-drug interactions (DDIs), particularly a suboptimal LNG exposure when co-administered with CYP3A4 inducers, potentially leading to unintended pregnancies. The goal of this analysis was to determine the impact of DDIs on the systemic exposure of LNG. To this end, we developed and verified a physiologically-based pharmacokinetic (PBPK) model for LNG in PK-Sim (version 8.0) accounting for the impact of EE and body mass index (BMI) on LNG's binding to sex-hormone binding globulin. Model parameters were optimized following intravenous and oral administration of 0.09 mg LNG. The combined LNG-EE PBPK model was verified regarding CYP3A4-mediated interaction by comparing to published clinical DDI study data with carbamazepine, rifampicin, and efavirenz (CYP3A4 inducers). Once verified, the model was applied to predict systemic LNG exposure in normal BMI and obese women (BMI ≥ 30 kg/m 2 ) with and without co-administration of itraconazole (competitive CYP3A4 inhibitor) and clarithromycin (mechanism-based CYP3A4 inhibitor). Total and free LNG exposures, when co-administered with EE, decreased 2-fold in the presence of rifampin, whereas they increased 1.5-fold in the presence of itraconazole. Although changes in total and unbound exposure were decreased in obese women compared with normal BMI women, the relative impact of DDIs on LNG exposure was similar between both groups., (© 2020 The Authors. CPT: Pharmacometrics & Systems Pharmacology published by Wiley Periodicals LLC on behalf of the American Society for Clinical Pharmacology and Therapeutics.)

Antiretroviral therapy has slowed the HIV/AIDS pandemic and is currently being used as a prophylactic measure for individuals at high risk of infection. However, concerns over adverse effects of long-term use need to be explored. We hypothesize that this may occur, at least in part, through off-target effects via select steroid receptors (SRs) that broadly regulate multiple physiological processes. We investigated the effects of maraviroc (MVC), tenofovir disoproxil fumarate (TDF), and dapivirine (DPV) on progesterone receptor B (PR-B) transcriptional activity. We found that MVC and TDF activate PR-B transcription in the absence of progestogens on a PR-regulated promoter reporter construct and on endogenous PR-regulated genes. MVC and TDF exhibited no direct binding to PR-B; however, increased PR-B phosphorylation was detected with TDF but not MVC. DPV transactivated gilz and ptgs2 in the absence of progestogens and exhibited PR-B binding while showing no effects on phosphorylation, suggesting that it may activate PR-B through a direct mechanism. Our study shows that potential off-target immunomodulatory effects of MVC, TDF and DPV occur in vitro and these are most likely mediated by different mechanisms of PR-B activation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Objective: To compare systemic exposure to levonorgestrel (LNG) released from commercially available intrauterine systems (IUSs), a subdermal implant, and oral contraceptives., Methods: An integrated population pharmacokinetic (popPK) analysis of data from over 3400 individuals in ten clinical studies with six different LNG-releasing contraceptives (four long-acting reversible contraceptives [LARCs: LNG-IUS 8, 12, and 20, initially releasing LNG 14, 17.5, and 20 μg/day, a subdermal implant initially releasing LNG 100 μg/day according to label]; progestin-only pill [POP: LNG 30 μg/day]; and combined oral contraceptive [COC] pill [LNG 100 μg/day and ethinylestradiol 20 μg/day]), was conducted to generate a popPK model. LNG release rates, and total and unbound serum/plasma LNG concentrations with LARCs were estimated over the indicated period of use; maximum (C max ) and average (C av ) serum LNG concentrations were estimated at steady state for oral contraceptives. Influence of body weight on LNG PK was also investigated., Results: Serum LNG concentration with LARCs increased with increasing daily LNG release rate, being lowest with LNG-IUS 8, higher with LNG-IUS 12 and LNG-IUS 20, and highest with the subdermal implant (1.7-2.1-times that with LNG-IUS 20). Compared with early serum LNG concentrations with LNG-IUS 20, C av and C max were 1.7- and 4.5-fold higher with POP, and 8.6- and 18-fold higher with COC. Total LNG bioavailability was >97% for the LNG-IUSs and 66-80% with other contraceptives. Serum/plasma LNG concentrations decreased with increasing body weight., Conclusions: Among the contraceptives examined, COC had the highest and LNG-IUSs the lowest systemic exposure to LNG. Systemic LNG concentration was inversely correlated to body weight.

Ibrutinib may inhibit intestinal CYP3A4 and induce CYP2B6 and/or CYP3A. Secondary to potential induction, ibrutinib may reduce the exposure and effectiveness of oral contraceptives (OCs). This phase I study evaluated the effect of ibrutinib on the pharmacokinetics of the CYP2B6 substrate bupropion, CYP3A substrate midazolam, and OCs ethinylestradiol (EE) and levonorgestrel (LN). Female patients (N = 22) with B-cell malignancies received single doses of EE/LN (30/150 μg) and bupropion/midazolam (75/2 mg) during a pretreatment phase on days 1 and 3, respectively (before starting ibrutinib on day 8), and again after ibrutinib 560 mg/day for ≥ 2 weeks. Intestinal CYP3A inhibition was assessed on day 8 (single-dose ibrutinib plus single-dose midazolam). Systemic induction was assessed at steady-state on days 22 (EE/LN plus ibrutinib) and 24 (bupropion/midazolam plus ibrutinib). The geometric mean ratios (GMRs; test/reference) for maximum plasma concentration (C max ) and area under the plasma concentration-time curve (AUC) were derived using linear mixed-effects models (90% confidence interval within 80%-125% indicated no interaction). On day 8, the GMR for midazolam exposure with ibrutinib coadministration was ≤ 20% lower than the reference, indicating lack of intestinal CYP3A4 inhibition. At ibrutinib steady-state, the C max and AUC of EE were 33% higher than the reference, which was not considered clinically relevant. No substantial changes were noted for LN, midazolam, or bupropion. No unexpected safety findings were observed. A single dose of ibrutinib did not inhibit intestinal CYP3A4, and repeated administration did not induce CYP3A4/2B6, as assessed using EE, LN, midazolam, and bupropion., (© 2020 The Authors. Pharmacology Research & Perspectives published by John Wiley & Sons Ltd, British Pharmacological Society and American Society for Pharmacology and Experimental Therapeutics.)

The incidence of migraine is higher among women than men and peaks during the reproductive years, when contraceptive medication use is common. Atogepant, a potent, selective antagonist of the calcitonin gene-related peptide receptor-in development for migraine prevention-is thus likely to be used by women taking oral contraceptives. This phase 1, open-label, single-center, 2-period, fixed-sequence study examined the effect of multiple-dose atogepant 60 mg once daily on the single-dose pharmacokinetics of a combination oral contraceptive, ethinyl estradiol 0.03 mg and levonorgestrel 0.15 mg (EE/LNG), in healthy postmenopausal or oophorectomized women. For participants in period 1, a single dose of EE/LNG was followed by a 7-day washout. In period 2, atogepant was given once daily on days 1-17; an oral dose of EE/LNG was coadministered with atogepant on day 14. Plasma pharmacokinetic parameters for EE and LNG were assessed following administration with and without atogepant. Twenty-six participants aged 45-64 years enrolled; 22 completed the study in accordance with the protocol. The area under the concentration-time curve extrapolated to infinity (AUC 0-∞ ) of LNG was increased by 19% when administered with atogepant. Coadministration of atogepant and a single dose of EE/LNG did not substantially alter the pharmacokinetics of EE; the ∼19% increase in plasma AUC 0-∞ of LNG is not anticipated to be clinically significant. Overall, atogepant alone and in combination with EE/LNG was generally well tolerated, with no new safety signals identified., (© 2020 Merck Sharp & Dohme Corp. The Journal of Clinical Pharmacology published by Wiley Periodicals, Inc. on behalf of American College of Clinical Pharmacology.)

Poor patient adherence to oral contraceptives is the predominant cause of failure of these therapies, leading to unplanned pregnancies that can negatively affect female health worldwide. To improve patient adherence, we developed an oral contraceptive that is administered once a month. Here, we describe the design and report in vivo characterization of a levonorgestrel-releasing gastric resident dosage form in pigs., (Copyright © 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

Intravaginal rings (IVRs) are an option for continuous administration of drugs in women. As an attractive approach for the treatment of endometriosis-associated pelvic pain, IVRs delivering a combination of the aromatase inhibitor anastrozole (ATZ) and the progestin levonorgestrel (LNG) have been developed. This article describes the developmental pharmacokinetic (PK) aspects covering the characterization of in vitro release, preclinical IVR PK investigations in monkeys, and clinical PK considerations. An IVR for ATZ has been developed and investigated in healthy menstruating female cynomolgus monkeys showing effective in vivo release. PK data from the size-adapted IVR used in these animals can be translated into a human context as confirmed in human studies where predefined exposure levels of ATZ were reached. As ATZ may cause harm to the fetus, use of effective contraception has to be assured in women of childbearing potential. Therefore, the IVR delivers a low dose of LNG as a contraceptive. Although the daily dose differed strongly between both drugs (20 µg LNG/d to >1 mg ATZ/d), simultaneous delivery of ATZ and LNG in vitro and in vivo was observed with a high correlation between the in vitro release and PK profiles. The PK characteristics successfully guided the design of clinical studies investigating the drug-drug interaction (DDI) potential. No relevant DDI between both the investigated or other vaginally administered drugs were identified.

Objectives: To evaluate pharmacokinetics and pharmacogenetics of contraceptive implant progestin concentrations in HIV-positive women initiating efavirenz (EFV)-containing or nevirapine (NVP)-containing antiretroviral therapy (ART)., Design: We analyzed stored samples from women self-reporting implant use in the Partners PrEP Study., Methods: Plasma samples collected every 6 months were analyzed for levonorgestrel and etonogestrel concentrations. Progestin concentrations from samples collected after ART initiation were compared with pre-ART concentrations for intraindividual comparisons. We used adjusted linear mixed models to compare hormone concentrations between individuals on EFV and NVP to a no ART group. We then evaluated whether possessing certain alleles with known or possible influences on EFV, NVP, or progestin metabolism were associated with changes in progestin concentrations or modified the association between ART use and progestin concentrations., Results: Our analysis included 11 women who initiated EFV, 13 who initiated NVP, and 36 who remained ART-naive. In the EFV group, the adjusted geometric mean ratio (aGMR) of levonorgestrel was 0.39 [90% confidence intervals (0.31, 0.49); P < 0.001] and the etonogestrel aGMR was 0.51 (0.34, 0.76; P = 0.006) compared with the control group. No difference was observed in the NVP group compared with controls [levonorgestrel 0.93 (0.74, 1.18); P = 0.64; etonogestrel 1.07 (0.77, 1.50); P = 0.73]. Possession of four allele variants were found to result in further reductions in progestin concentrations among those receiving EFV., Conclusion: Concomitant use of EFV significantly reduces levonorgestrel or etonogestrel concentrations by 61 and 49%, respectively, compared with no ART use. We also report allelic variants in hepatic enzymes that influenced the extent of the observed drug-interaction between progestins and EFV.

Objective: To assess the pharmacokinetics of combined oral contraceptive (COC) components and prevalence of ovulation in HIV-positive women using ritonavir-containing antiretroviral regimens compared to those using regimens previously found not to interact with COCs or not using any antiretrovirals., Study Design: We conducted a prospective cohort pharmacokinetic pilot study comparing the pharmacokinetics of levonorgestrel (LNG) and ethinyl estradiol (EE) in HIV-positive women taking ritonavir-containing antiretroviral regimens to those in women using non-ritonavir-containing regimens or no antiretrovirals. Participants received COCs containing LNG/EE 150/30 mcg for 21 days. Beginning day 21, we collected serial blood samples over 72 h. The primary outcome was area under the curve (AUC) of LNG, with secondary outcomes including other LNG pharmacokinetic measures, EE pharmacokinetics and ovulation as measured by serum progesterone., Results: Pharmacokinetic parameters of LNG showed a trend toward increased exposure in women on ritonavir. LNG AUC last increased by 32.6% (312±60.9 vs. 243±82.6 ng/mL*h, p=.033, n=5) in women taking ritonavir compared to the control group (n=10). The C max (9.68±1.81 vs. 7.62±2.29 ng/mL) and C min (4.97±1.15 vs. 3.70±1.29 ng/mL) were also higher in the ritonavir arm. After excluding the inconsistent users (n=2), CL of LNG was reduced in the ritonavir arm (p=.032). EE pharmacokinetic profiles were not different between groups. The progesterone concentrations were similar in women of both groups, and none were consistent with ovulation during the treatment cycle., Conclusion: Women on ritonavir showed an approximately 30% increase in LNG exposure but no difference in EE exposure., Implications: The current data suggest that ritonavir does not have a clinically significant impact on oral contraceptive pharmacokinetics., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Study Objective: The aim of this study was to review the efficacy of different medical modalities for menstrual suppression in the cohort of patients with disabilities who presented to the Queensland Paediatric and Adolescent Gynaecology (PAG) Service between January 2005 and December 2015. Menstrual suppression in adolescents with disabilities is an important aspect of care to support the patient and their carers in managing the complexities of menstrual hygiene, pain, and other discomfort associated with menses. It is important for general practitioners, pediatricians, and gynecologists to establish the right modality of suppression for each individual adolescent. DESIGN, SETTINGS, PARTICIPANTS, INTERVENTIONS, AND MAIN OUTCOME MEASURES: The study was a retrospective case notes review of 68 adolescents who presented to the Queensland PAG Service, Brisbane, Australia with a request for menstrual suppression. The medical interventions included treatment with either combined oral hormonal contraceptive, oral medroxyprogesterone, depot medroxyprogesterone, or the levonorgestrel intrauterine system (Mirena, Bayer). The primary outcome measure was success of menstrual suppression from commencement of medical intervention to achievement of complete amenorrhea or very light bleeding described as spotting, for each medical modality. Secondary outcomes were length of time from first treatment to first observed menstrual suppression, and the number of outpatient appointments taken to achieve menstrual suppression., Results: Of the 68 adolescents, 59/68 (86.8%) successfully achieved menstrual suppression, with 9/68 (13.2%) having ongoing treatment or loss to follow-up at the time of conclusion of the study; 39/68 (57.4%) were menstrually suppressed with their chosen medical modality after their initial appointment., Conclusion: Medical modalities are highly effective in achieving menstrual suppression and no young women at this institution required a hysterectomy. Depot medroxyprogesterone was the most successful modality used to achieve menstrual suppression followed by the levonorgestrel intrauterine system. The combined oral hormonal contraceptive was the least successful medical treatment in achieving menstrual suppression., (Crown Copyright © 2019. Published by Elsevier Inc. All rights reserved.)

Objective: Letermovir is an inhibitor of the terminase complex of cytomegalovirus (CMV) used as prophylactic therapy in CMV-seropositive allogeneic hematopoietic stem cell transplant recipients. As the combination oral contraceptive (COC) levonorgestrel/ethinyl estradiol (LNG/EE) may be coadministered in this target transplant population, the effects of letermovir on the pharmacokinetics (PK) of LNG and EE were investigated., Materials and Methods: This was a phase I, open-label, fixed-sequence, two-period study conducted in healthy women (18 - 65 years old) of non-childbearing potential (protocol number: MK-8228 035). On day 1 of period 1, participants received a single dose of COC (LNG 0.15 mg/EE 0.03 mg). Following a 7-day washout, oral letermovir 480 mg was administered once-daily on days 1 - 12 of period 2, with a single dose of COC coadministered on day 8. Blood samples were collected to determine LNG and EE PK, and safety was assessed., Results: The AUC 0-∞ geometric mean ratios (90% confidence intervals) for COC + letermovir/COC alone were 1.36 (1.30, 1.43) for LNG and 1.42 (1.32, 1.52) for EE, indicating that letermovir coadministration increased COC exposure. Coadministration had no clinically-meaningful effect on C max , t max , or apparent terminal T 1/2 for either LNG or EE. All treatments were generally well tolerated., Conclusion: Letermovir coadministration with COC resulted in an increase in LNG and EE exposure in healthy adult women; however, levels were within the established safety margins. There was no decrease in LNG or EE exposure with no apparent risk of contraceptive failure on coadministration of letermovir and COC.
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Intravaginal rings (IVRs) are an established option for continuous administration of drugs in women. The combination of anastrozole (ATZ) and levonorgestrel (LNG) in an IVR with an intended 4-week wearing period has been considered for long-term treatment of endometriosis-associated pelvic pain. A randomized, parallel-group, multicenter phase 2b study to assess the efficacy and safety of different dose combinations in women with symptomatic endometriosis has recently been performed. This paper will focus on the investigation of pharmacokinetic (PK) effects of ATZ on LNG using data collected from this study. Two hundred sixteen patients were randomized to the treatment group with IVRs releasing LNG 40 μg/day alone or in combination with ATZ 300 μg/day, 600 μg/day, or 1050 μg/day for 12 weeks. PK blood samples were taken before dosing and before IVR replacement or removal (days 28, 56, and 84). The primary PK parameter was the plasma concentration in apparent steady state of ATZ and LNG at the end of each IVR wearing period. Results of PK analysis demonstrate that ATZ concentrations increased proportionally with increasing dose (geometric mean values of 7.85, 15.48, and 22.61 μg/L at 300, 600, and 1050 μg/day nominal release, respectively). All point estimates for LNG concentration in apparent steady state ratios between the mono and combination IVR groups were close to 1, and the 90% confidence interval limits were in the 0.80 to 1.25 range (1.01 [0.85-1.19], 1.03 [0.88-1.20], 0.94 [0.80-1.10]). In conclusion, our data indicate there is no evidence of drug-drug interaction of ATZ on LNG., (© 2019, The Authors. The Journal of Clinical Pharmacology published by Wiley Periodicals, Inc. on behalf of American College of Clinical Pharmacology.)

Lack of adherence to medication dosing schedules is a significant cause of morbidity and mortality with large associated financial costs. This is especially true for contraceptive hormones, which provide almost perfect prevention of pregnancy when used correctly, but have significant failure rates in typical use, due largely to poor adherence. To increase medication acceptability and adherence, we introduce pharmaceutical jewelry, in which a transdermal patch is incorporated into jewelry worn on skin. To demonstrate the approach, we incorporated transdermal patches containing the contraceptive hormone levonorgestrel (LNG) into an earring, a ring, a necklace, and a wrist watch. Transdermal delivery of LNG from earring patches across porcine skin ex vivo achieved a steady state flux of 1.7 μg/cm 2 ·h. Pharmacokinetic analysis in hairless rats yielded LNG delivery rates that maintained serum LNG levels near 1500 pg/ml throughout the 1-week patch application period, which is well above the human contraceptive threshold concentration of 200 pg/ml. When patches were applied cyclically for 16 h on and 8 h off to simulate earring removal at night, serum LNG concentrations dipped during off periods, but remained well above the human contraceptive threshold. Earring patches were well tolerated by the rats. We conclude that pharmaceutical jewelry can provide a novel method of drug delivery, especially for contraceptive hormones, that has the potential to improve acceptability and increase medication adherence., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Objective: To assess the pharmacokinetics (PK) of levonorgestrel after 1.5 mg oral doses (LNG-EC) in women with normal, obese and extremely obese body mass index (BMI)., Study Design: The 1.5 mg LNG dose was given to healthy, reproductive-age, ovulatory women with normal BMI (mean 22.0), obese (mean 34.4), and extremely obese (mean 46.6 kg/m 2 ) BMI. Total serum LNG was measured over 0 to 96 h by radioimmunoassay while free and bioavailable LNG were calculated. The maximum concentration (Cmax), time to maximum concentration (Tmax), and area under the curve (AUC) of LNG were assessed. Pharmacokinetic parameters calculated included half-life (t1/2), clearance (CL) and volume of distribution (Vss)., Results: Ten normal-BMI, 11 obese-BMI, 5 extremely obese-BMI women were studied. After LNG-EC, mean total LNG metrics were lower in the obese and extremely obese groups compared to normal (Cmax 10.5 and 10.5 versus 16.2 ng/mL, both p<.01; AUC 208 and 197 versus 360 h × ng/mL, both p<.05). Mean bioavailable LNG Cmax was lower in obese (7.03 ng/mL, p<.05) and extremely obese (7.53 ng/ml, p=.198) compared to normal BMI (9.39 ng/mL). Mean bioavailable LNG AUC values were lower in obese and extremely obese compared to normal (131.6 and 127.5 vs 185.0 h × ng/mL, p<.05 for both)., Conclusions: Obese and extremely obese women were exposed to lower total and bioavailable LNG than normal BMI women., Implications: Lower 'bioavailable' (free plus albumin bound) LNG AUC in obese women may play a role in the purported reduced efficacy of LNG-EC in obese users., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Objective: The objective was to evaluate the pharmacokinetics (PKs) of levonorgestrel (LNG)-containing combined oral contraceptives (COCs) in obese women., Study Design: We pooled and reanalyzed data from 89 women with different body mass index (BMI) categories from four clinical studies. The LNG and ethinyl estradiol (EE) PKs were analyzed utilizing a zero-order absorption (K 0 ), two-compartment PK model to evaluate key PK parameters in relation to a range of weights, BMI and body surface area (BSA)., Results: Increasing of body habitus metrics is correlated with decreasing C max (p<.0001) and AUC τ (p<.05) for both LNG and EE, but no correlation was found for C min (p≥.17). Increasing weight and BMI were associated with a modest increase (p≤.056) of clearance (CL) and appreciable increases of central volume (V 1 , p<.05), distribution clearance (CLd, p≤.001) and peripheral volume (V 2 , p<.0001) for LNG. For EE, increases in CL (p≤.009) were found with greater weight, BMI and BSA. Values of V 1 , CLd and V 2 also increased (p<.0001) in obese subjects. The half-life and steady-state volume were greater among obese women (p<.0001) for both LNG and EE. LNG and EE PK parameters correlated well (p≤.006 for all), indicating that individual subject physiology affected both drugs similarly., Conclusions: The primary effects of obesity on LNG and EE were a modest increase in CL and a marked increase in distribution parameters. We observed no obesity-related differences in trough LNG and EE concentrations., Implications: This population PK analysis demonstrated reduced systemic exposure to LNG/EE oral contraceptives in obese subjects (C max and AUC τ ); these particular differences are unlikely to lower contraceptive effectiveness among obese women who are correctly using LNG-containing contraceptives., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Upadacitinib is a novel selective oral Janus kinase 1 (JAK) inhibitor being developed for treatment of several inflammatory diseases. Oral contraceptives are anticipated to be a common concomitant medication in the target patient populations. This study was designed to evaluate the effect of multiple doses of upadacitinib on the pharmacokinetics of ethinylestradiol and levonorgestrel in healthy female subjects. This phase I, single-center, open-label, 2-period crossover study evaluated the effect of multiple doses of 30 mg once daily extended-release upadacitinib on the pharmacokinetics of a single oral dose of ethinylestradiol/levonorgestrel (0.03/0.15 mg; administered alone in period 1 and on day 12 of a 14-day regimen of upadacitinib in period 2) in 22 healthy female subjects. The ratios (90% confidence intervals) for maximum plasma concentration and area under the plasma drug concentration-time curve from time zero to infinity following administration of ethinylestradiol/levonorgestrel with upadacitinib compared with administration of ethinylestradiol/ levonorgestrel alone were 0.96 (0.89-1.02) and 1.1 (1.04-1.19), respectively, for ethinylestradiol, and 0.96 (0.87-1.06) and 0.96 (0.85-1.07), respectively, for levonorgestrel. The harmonic mean terminal half-life for ethinylestradiol (7.7 vs 7.0 hours) and levonorgestrel (37.1 vs 33.1 hours) was similar in the presence and absence of upadacitinib. Ethinylestradiol and levonorgestrel were bioequivalent in the presence and absence of upadacitinib. Therefore, upadacitinib can be administered concomitantly with oral contraceptives containing ethinylestradiol or levonorgestrel., (© 2018, The Authors. The Journal of Clinical Pharmacology published by Wiley Periodicals, Inc. on behalf of American College of Clinical Pharmacology.)

Women often have limited access to contraception, and barrier methods have low acceptance and a high failure rate, mostly due to incorrect use, which can result in unplanned pregnancies. Sustained-release formulations of contraceptive hormones are available, yet typically require their administration by trained personnel. Here, we report the design of a microneedle patch with rapidly separable biodegradable polylactic acid and polylactic-co-glycolic acid needles, and its application for the continuous release of levonorgestrel-a contraceptive hormone. Bubble structures between each microneedle and the patch backing allow the microneedles to efficiently penetrate skin under compression, and to snap off under shear within five seconds after patch administration. In rats, the microneedle patch was well tolerated, leaving little visible evidence of use, and maintained plasma concentrations of the hormone above the human therapeutic level for one month. Further development of the rapidly separable microneedle patch for self-administered, long-acting contraception could enable women to better control their fertility.

Purpose: Laquinimod is an orally dosed immuno-modulator currently under development for Huntington's disease (HD). Preclinical findings suggest potential teratogenicity of laquinimod, thus the reproductive ability of females with HD treated with laquinimod needs to be closely managed. Because combined oral contraceptives (COC) are often used in this context, the pharmacokinetics of COC containing ethinylestradiol (EE) and levonorgestrel (LNG) in combination with laquinimod (0.6 mg/day) was evaluated., Methods: In this randomized, phase-1 single-center, double-blind, placebo-controlled, 2-way crossover drug-drug interaction (DDI) study in 48 healthy premenopausal women, COC were administered in a 28-day regimen of 21 days followed by 7 pill-free days for 4 cycles and laquinimod or placebo was administered for 28 days in cycle 1 and cycle 3 starting 7 days prior to COC administration. Blood samples for pharmacokinetic profiling of laquinimod, EE and LNG were collected on day 21 and day 22 of Cycles 1 and 3 pre-dose and multiple times post-dose., Results: The ratio of geometric means and 90% confidence intervals for AUC 0-24 and C max of EE and LNG with and without laquinimod were all within the bioequivalence range (80 to 125%). Laquinimod pharmacokinetics was consistent with those observed in previous studies. The adverse event profile was in line with the current knowledge on the safety profile of both drugs, with headache as the most frequently reported treatment-related adverse event., Conclusion: The combination of COC and laquinimod treatment was found to be safe, tolerable, and devoid of any noticeable pharmacokinetic interaction.

To compare the pharmacokinetics (PK) of the progestin levonorgestrel for various routes of administration, an integrated population PK analysis was performed. This analysis integrated data from 10 clinical pharmacology studies and resulted in a single, comprehensive population PK model (and its applications) describing the PK of levonorgestrel and its variability for 6 levonorgestrel-containing contraceptives: 3 intrauterine systems (IUSs; levonorgestrel [LNG]-IUS 20 [Mirena ® ], LNG-IUS 12 [Kyleena ® ], and LNG-IUS 8 [Jaydess ® /Skyla ® ]); 2 oral contraceptives (the progestin-only pill [Microlut ® /Norgeston ® ] and the combined oral contraceptive [Miranova ® ]); and a subdermal implant (Jadelle ® ). The levonorgestrel-containing contraceptives administered orally or as an implant act mainly via their systemic (unbound) levonorgestrel exposure, whereas levonorgestrel administered via an IUS is released directly into the uterine cavity, resulting in lower systemic levonorgestrel concentrations. The integrated population PK analysis revealed that the combined oral contraceptive led to the highest levonorgestrel exposure, followed by the progestin-only pill and the implant, which led to similar levonorgestrel exposure, and the IUSs, which led to the lowest levonorgestrel exposure (in decreasing order: LNG-IUS 20, LNG-IUS 12, and LNG-IUS 8). The difference was even more distinct at the end of the indicated duration of use of 3 years (LNG-IUS 8) and 5 years (LNG-IUS 20 and LNG-IUS 12). Comparing the 3 IUSs and the implant, in vivo release rates were highest for the implant, followed by LNG-IUS 20, then LNG-IUS 12, and were lowest for LNG-IUS 8. This is in line with the comparison of the total levonorgestrel concentrations., (© 2018, The American College of Clinical Pharmacology.)

A specific and sensitive high-performance liquid chromatography-tandem mass spectrometry method that could be used to determine the concentration of levonorgestrel (LNG) in beagle dog plasma was developed. Specifically, terfenadine was used as the internal standard (IS). The separation was achieved on a Kinetex-C 18 110A column (3 × 30 mm i.d., 2.6 um, Phenomenex) and a gradient mobile phase consists of methanol (0.1% formic acid) and water (0.1% formic acid) was used. The flow rate was 0.8 mL/min and the injection volume was 10 μL. The detection was performed on a triple-quadruple tandem mass spectrometer by multiple reaction monitoring mode via electrospray ionization. Quantitative analysis was carried out at m/z 313.0 → 108.9 and m/z 472.6 → 436.2 for LNG and IS respectively. This method demonstrated the linearity of LNG over a concentration range of 0.5-50 ng/mL with a coefficient correlation (r) of 0.9973. The lower limit of quantification was 0.5 ng/mL. The intra- and inter-assay precisions were 2.9 and 11.2%, with an accuracy range from 94.8 to 108.4%. The stability data indicated that sample preparation and storage process had little effect on the concentration of LNG QC sample. The validated method was successfully applied to study the pharmacokinetics of LNG in beagle dog after vaginal administration of intravaginal ring., (© 2018 John Wiley & Sons, Ltd.)

Objective: To report differences in ovarian stimulation outcomes in women using a levonorgestrel-releasing intrauterine device (LNG-IUD)., Design: Retrospective cohort study., Setting: University-based infertility practice., Patient(s): Female patients pursuing either social oocyte cryopreservation or oocyte donation., Intervention(s): Chart review of all female patients presenting from January 1, 2012, to June 30, 2017, for social oocyte cryopreservation or oocyte donation. Demographic data, cycle performance data, and the presence or absence of an LNG-IUD at the time of ovarian stimulation were compared., Main Outcome Measure(s): Total oocyte yield and total mature oocyte yield. Secondary measures included clinical pregnancy rate and live birth rate in recipients of donor oocytes., Result(s): Univariate analysis of predicted oocyte yield and mature oocyte yield showed no significant difference between subjects with and without an LNG. When controlling for history of recent hormonal contraceptive use, initial antral follicle count (AFC), age, body mass index (BMI), gonadotropin dose, and stimulation day/protocol, no significant differences were seen in total oocyte yield or mature oocyte yield in the presence or absence of an LNG-IUD. Univariate analysis of the effect of LNG-IUDs on the predicted clinical pregnancy rate and live birth rate did not significantly differ for oocyte recipients. Controlling for history of recent hormonal contraceptive use, initial AFC, age, BMI, gonadotropin dose, and stimulation day/protocol also showed no significant differences in the predicted clinical pregnancy rate and live birth rate., Conclusion(s): LNG-IUDs do not affect cycle performance in women undergoing ovarian stimulation cycles., (Copyright © 2018 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.)

To prevent the global health burdens of human immunodeficiency virus [HIV] and unintended/mistimed pregnancies, we developed an intravaginal ring [IVR] that delivers tenofovir [TFV] at ~10mg/day alone or with levonorgestrel [LNG] at ~20μg/day for 90 days. We present safety, pharmacokinetics, pharmacodynamics, acceptability and drug release data in healthy women. CONRAD A13-128 was a randomized, placebo controlled phase I study. We screened 86 women; 51 were randomized to TFV, TFV/LNG or placebo IVR [2:2:1] and 50 completed all visits, using the IVR for approximately 15 days. We assessed safety by adverse events, colposcopy, vaginal microbiota, epithelial integrity, mucosal histology and immune cell numbers and phenotype, cervicovaginal [CV] cytokines and antimicrobial proteins and changes in systemic laboratory measurements, and LNG and TFV pharmacokinetics in multiple compartments. TFV pharmacodynamic activity was measured by evaluating CV fluid [CVF] and tissue for antiviral activity using in vitro models. LNG pharmacodynamic assessments were timed based on peak urinary luteinizing hormone levels. All IVRs were safe with no significant colposcopic, mucosal, immune and microbiota changes and were acceptable. Among TFV containing IVR users, median and mean CV aspirate TFV concentrations remained above 100,000 ng/mL 4 hours post IVR insertion and mean TFV-diphosphate [DP] concentrations in vaginal tissue remained above 1,000 fmol/mg even 3 days post IVR removal. CVF of women using TFV-containing IVRs completely inhibited [94-100%] HIV infection in vitro. TFV/LNG IVR users had mean serum LNG concentrations exceeding 300 pg/mL within 1 hour, remaining high throughout IVR use. All LNG IVR users had a cervical mucus Insler score <10 and the majority [95%] were anovulatory or had abnormal cervical mucus sperm penetration. Estimated in vivo TFV and LNG release rates were within expected ranges. All IVRs were safe with the active ones delivering sustained high concentrations of TFV locally. LNG caused changes in cervical mucus, sperm penetration, and ovulation compatible with contraceptive efficacy. The TFV and TFV/LNG rings are ready for expanded 90 day clinical testing. Trial registration ClinicalTrials.gov #NCT02235662., Competing Interests: The authors have declared that no competing interests exist.

Levonorgestrel (LNG) is a synthetic progestin that is available in oral contraceptive tablets, a subdermal implant, and an intrauterine system for contraception. LNG pharmacokinetics are a pivotal determinant of contraceptive efficacy and essential in assessing drug-drug interactions influencing LNG exposure following different routes of LNG administration. A highly sensitive LC-MS/MS method was developed and validated to quantify levonorgestrel in human plasma. Liquid-liquid extraction was utilized with a sample volume of 500 μL to extract levonorgestrel from plasma. Chromatographic separation of LNG was achieved with a Fortis™ C18 (3 μm: 100 mm × 2.1 mm) reverse phase analytical column. The mobile phases consisted of de-ionized water plus 0.1% NH 4 OH (100:0.1%, v/v) (A), and methanol plus 0.1% NH 4 OH (100:0.1%, v/v) (B) delivered as a gradient at a flow rate of 400 μL/min. Detection of LNG and internal standard (D-(-)-norgestrel-d7) was achieved using positive polarity mode monitoring at 313.2-245.2 amu and 320.1-251.2 amu, respectively. The assay was linear over the calibration range of 49.6 to 1500 pg/mL. This method was used to quantify plasma LNG released by subdermal implant in support of a drug interaction study among women with HIV receiving efavirenz- or nevirapine-based antiretroviral therapy., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Intravaginal rings (IVRs) are an option for continuous administration of drugs in women. However, a considerable amount of excess drug often remains in the ring upon removal. The current study focuses on comparing 2 IVRs releasing levonorgestrel (LNG). Both formulations were designed to release 40 μg of LNG daily, however, with a significant difference in the total amount of drug (10.6 vs. 176.9 mg). Numerical simulations and in vitro release rate testing were utilized in designing the IVRs and confirming the similarity of drug release. Moreover, a pharmacokinetic (PK) study was performed in 13 healthy Japanese women to investigate both formulations during the intended wearing period of 28 days. The primary PK metrics was the average concentration of LNG in plasma at defined time points under stable conditions. Statistical evaluation of the ratio of the main PK metrics indicated values almost in the bioequivalence range. Furthermore, drug content determinations for used and unused IVRs were analyzed for confirming the expected drug delivery in vivo. In summary, it was shown that with proper design, even major differences in the total drug content of IVR formulations might not result in significant effects in the in vitro and in vivo release properties., (Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.)

Background: HIV-positive women receiving efavirenz-based ART and levonorgestrel contraceptive implants are at risk of low levonorgestrel exposure and unintended pregnancy., Objectives: To investigate clinically applicable dose-adjustment strategies to overcome the known drug-drug interaction (DDI) between levonorgestrel and efavirenz, using a physiologically based pharmacokinetic (PBPK) modelling-based approach., Methods: A PBPK model was qualified against clinical data to predict levonorgestrel plasma concentrations when standard-dose (150 mg) levonorgestrel implants were administered alone (control group), as well as when standard-dose or increased-dose (300 mg) levonorgestrel implants were coadministered with either 600 or 400 mg of efavirenz., Results: No difference was seen between in vivo clinical and PBPK-model-simulated levonorgestrel plasma concentrations (P > 0.05). Simulated levonorgestrel plasma concentrations were ∼50% lower at 48 weeks post-implant-placement in virtual individuals receiving standard-dose levonorgestrel with either 600 or 400 mg of efavirenz compared with the control group (efavirenz:control geometric mean ratio = 0.42 and 0.49, respectively). Conversely, increased-dose levonorgestrel in combination with either 600 or 400 mg of efavirenz was sufficient to restore levonorgestrel concentrations to levels similar to those observed in the 150 mg levonorgestrel control group 48 weeks post-implant-placement (efavirenz:control geometric mean ratio = 0.86 and 1.03, respectively)., Conclusions: These results suggest that the clinically significant DDI between efavirenz and levonorgestrel is likely to persist despite efavirenz dose reduction, whereas dose escalation of implantable levonorgestrel may represent a successful clinical strategy to circumvent efavirenz-levonorgestrel DDIs and will be of use to inform clinical trial design to assess coadministration of efavirenz and levonorgestrel implants.

Purpose: This study aimed to investigate the effect of steady-state exposure to flibanserin, a 5-HT 1A agonist/5-HT 2A antagonist approved for the treatment of hypoactive sexual desire disorder in premenopausal women, on the single-dose pharmacokinetics of the contraceptive steroids ethinylestradiol and levonorgestrel in healthy premenopausal women., Methods: Healthy female volunteers (N = 24) received 2 single doses of a combined oral contraceptive containing ethinylestradiol 30 μg and levonorgestrel 150 μg, either alone (reference) or preceded by treatment with flibanserin 100 mg once daily for 14 days (test). The 2 treatments were given in randomized order, with a 4-week washout period following the last administration of the first treatment. Plasma concentrations of ethinylestradiol and levonorgestrel were measured over 48 hours after dosing for the determination of pharmacokinetic parameters; the primary end points were C max and AUC 0-∞ of ethinylestradiol and levonorgestrel., Findings: Of the 24 women enrolled (mean age, 38.0 years), 23 completed the study. Mean (SD) C max and AUC 0-∞ values of ethinylestradiol were 66.7 (16.3) pg/mL and 693 (268) pg · h/mL, respectively, following the oral contraceptive alone, and 72.7 (25.5) pg/mL and 740 (235) pg · h/mL, respectively, when the oral contraceptive was preceded by flibanserin. In both cases, the 90% CIs of the reference/test ratios of C max and AUC 0-∞ were within the range of 80% to 125%, indicating that flibanserin had no significant effect on the pharmacokinetic properties of ethinylestradiol. Similarly, the mean (SD) C max and AUC 0-∞ values of levonorgestrel were 5.0 (1.6) ng/mL and 52.2 (18.7) ng · h/mL, respectively, with the oral contraceptive alone, and 5.0 (1.6) ng/mL and 53.3 (20.4) ng · h/mL, respectively, following flibanserin; again, in both cases, the 90% CIs of the reference/test ratios were within the range of 80% to 125%, indicating that flibanserin had no significant effect on the pharmacokinetic properties of levonorgestrel. All adverse events were mild to moderate in intensity (incidence: 12.5% and 70.8% with ethinylestradiol/levonorgestrel treatment alone and following administration of flibanserin, respectively)., Implications: Pretreatment with flibanserin 100 mg once daily for 2 weeks did not produce a clinically relevant change in oral contraceptive drug exposure following single-dose administration of ethinylestradiol/levonorgestrel. This finding is relevant to women with hypoactive sexual desire disorder who might prefer oral contraceptives to other forms of birth control. EudraCT No: 2006-006960-46., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)

A study was performed to investigate the effect of an intravaginally administered antimycotic, an antibiotic, and a spermicide plus the co-usage of tampons on the pharmacokinetics (PK) of levonorgestrel (LNG) and anastrozole (ATZ) administered as an intravaginal ring (IVR) releasing 1050 μg ATZ per day and 40 μg LNG per day. In this parallel-group, randomized, open-label study, healthy premenopausal women received an IVR as the main treatment. Comedications were administered on 3 consecutive evenings during treatment with IVR on days 9-11 (group A, 400 mg miconazole; group B, 100 mg clindamycin; group C, 75 mg nonoxynol-9); tampon co-usage (group D) was performed on days 20-23. The primary PK parameter was the average plasma concentration (C av,ss ) of ATZ and LNG at defined intervals, mainly prior to, during, and up to 7 days after the start of comedication. Fifty-two subjects were included, and at least 11 subjects per group completed the treatments. Overall, the medications and comedications were safe and well tolerated. Very similar ATZ and LNG plasma levels were observed across all groups. The calculated ratios of C av,ss confirmed the absence of PK interactions because all relevant point estimates and 90% confidence intervals were within the range of 0.800-1.250, which is typically used in bioequivalence studies. These results demonstrate the absence of PK interactions between ATZ/LNG released from IVR and the tested antibiotic, antimycotic, spermicide, and tampons. Therefore, no restrictions for the use of the IVR are needed to continue the clinical program intended to treat endometriosis symptoms., (© 2017, The Authors. The Journal of Clinical Pharmacology published by Wiley Periodicals, Inc. on behalf of American College of Clinical Pharmacology.)

Reduced levonorgestrel concentrations from the levonorgestrel contraceptive implant was previously seen when given concomitantly with efavirenz. We sought to assess whether single nucleotide polymorphisms (SNPs) in genes involved in efavirenz and nevirapine metabolism were linked to these changes in levonorgestrel concentration. SNPs in CYP2B6, CYP2A6, NR1I2, and NR1I3 were analyzed. Associations of participant demographics and genotype with levonorgestrel pharmacokinetics were evaluated in HIV-positive women using the levonorgestrel implant plus efavirenz- or nevirapine-based antiretroviral therapy (ART), in comparison to ART-naïve women using multivariate linear regression. Efavirenz group: CYP2B6 516G>T was associated with lower levonorgestrel log 10 C max and log 10 AUC. CYP2B6 15582C>T was associated with lower log 10 AUC. Nevirapine group: CYP2B6 516G>T was associated with higher log 10 C max and lower log 10 C min . Pharmacogenetic variations influenced subdermal levonorgestrel pharmacokinetics in HIV-positive women, indicating that the magnitude of the interaction with non-nucleoside reverse transcriptase inhibitors (NNRTIs) is influenced by host genetics., (© 2017 American Society for Clinical Pharmacology and Therapeutics.)

Objective: This study compares the pharmacokinetics (PK) of levonorgestrel (LNG) emergency contraceptive (EC) and ulipristal acetate (UPA)-EC between normal-body mass index (BMI) and obese-BMI women., Study Design: This prospective, randomized crossover study evaluates the PK of women after single doses of LNG-EC (1.5mg) and UPA-EC (30mg). Study procedures took place during clinical research unit admissions, where participants received a standardized meal and each study drug, in random order, during two separate 24-h admissions. Study staff collected 14 blood specimens (0, 0.5, 1.0, 1.5, 2, 3, 4, 6, 8, 10, 12, 16, 24 and 48h). We evaluated serum concentrations of LNG and UPA using liquid chromatography-tandem mass spectroscopy and estimated the PK parameters of both drugs using noncompartmental analysis. The main outcome of this study was a comparison of between-group differences in AUC 0-24 ., Results: Thirty-two women completed the study (16 in each group). Among normal-BMI and obese-BMI participants, the mean BMIs were 22.0 (range 18.8-24.6) and 34.3 (range 30.6-39.9), respectively. After LNG-EC, mean AUC 0-24 and maximum concentration (C max ) were 50% lower among obese-BMI women than among normal-BMI women (AUC 0-24 100.8 vs. 208.5ng*h/mL, IQR obese-BMI 35.8, IQR normal-BMI 74.2, p≤.01; C max 10.8 vs. 18.2ng/mL, p=.01). After UPA-EC, AUC 0-24 and C max were similar between obese-BMI and normal-BMI women (AUC 0-24 362.5 vs. 293.5ng*h/mL, IQR obese-BMI 263.2, IQR normal-BMI 112.5, p=.15; C max 95.6 vs. 89.3ng/mL, p=.70)., Conclusion: After a single dose of EC, obese-BMI women are exposed to lower concentrations of LNG and similar concentrations of UPA, when compared to normal-BMI women., Implications: Differences in LNG-EC PK by BMI group may underlie and account for the lower LNG-EC efficacy reported among obese-BMI women, but modest differences in UPA-EC PK by BMI group provide less support for variable efficacy. A pharmacodynamic study may be able to clarify whether these PK differences account for observed differences in LNG-EC and UPA-EC efficacy., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Objectives: Venous thromboembolism (VTE) risk increases within months of combination oral contraceptive (COC) initiation. Because elevated endogenous thrombin potential (ETP) has been found in several studies to be a VTE risk factor, we evaluated the extent of ETP changes during the initial cycle of an ethinyl estradiol (EE) and levonorgestrel (LNG) COC. We also assessed the relationship between ETP changes and systemic EE and LNG concentrations., Study Design: Participants provided multiple blood samples during a first 21-day cycle of a 30-mcg EE/150-mcg LNG COC and after a further 7 days without an active COC. Thrombin generation measured with and without addition of activated protein C (APC) yielded ETP +APC and ETP -APC and the normalized APC sensitivity ratio (nAPCsr). EE and LNG pharmacokinetic analyses were conducted over 24 h after the first COC tablet and again at steady state., Results: Thrombin generation was determined in 16 of the 17 women who completed the study. Mean ETP -APC increased steadily to 21% above baseline at 24 h after the 6th COC tablet (COC6 24 ; p<.001) and to 28% above baseline at steady state (COC21; p<.001). The percentage increase in mean ETP +APC was considerably more - 54% at COC6 24 and 79% at steady state. Mean nAPCsr increased by 28% at COC6 24 and by 41% at steady state. Higher concentrations of EE or LNG were not correlated with greater increases in ETP., Conclusions: ETP increases during the first COC cycle were substantial., Implications: The early increases in ETP may provide biological support for the rapid increase in VTE risk during initial COC use. The lack of association between this clotting system perturbation and the systemic EE concentration is surprising and deserves further study., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Pharmacokinetics (PK) of anastrozole (ATZ) and levonorgestrel (LNG) released from an intravaginal ring (IVR) intended to treat endometriosis symptoms were characterized, and the exposure-response relationship focusing on the development of large ovarian follicle-like structures was investigated by modeling and simulation to support dose selection for further studies. A population PK analysis and simulations were performed for ATZ and LNG based on clinical phase 1 study data from 66 healthy women. A PK/PD model was developed to predict the probability of a maximum follicle size ≥30 mm and the potential contribution of ATZ beside the known LNG effects. Population PK models for ATZ and LNG were established where the interaction of LNG with sex hormone-binding globulin (SHBG) as well as a stimulating effect of estradiol on SHBG were considered. Furthermore, simulations showed that doses of 40 μg/d LNG combined with 300, 600, or 1050 μg/d ATZ reached anticipated exposure levels for both drugs, facilitating selection of ATZ and LNG doses in the phase 2 dose-finding study. The main driver for the effect on maximum follicle size appears to be unbound LNG exposure. A 50% probability of maximum follicle size ≥30 mm was estimated for 40 μg/d LNG based on the exposure-response analysis. ATZ in the dose range investigated does not increase the risk for ovarian cysts as occurs with LNG at a dose that does not inhibit ovulation., (© 2016, The American College of Clinical Pharmacology.)

Objective: The gold standard for measuring oral contraceptive (OC) pharmacokinetics is the 24-h steady-state area under the curve (AUC). We conducted this study to assess whether limited sampling at steady state or measurements following use of one or two OCs could provide an adequate proxy in epidemiological studies for the progestin 24-h steady-state AUC of a particular OC., Study Design: We conducted a 13-sample, 24-h pharmacokinetic study on both day 1 and day 21 of the first cycle of a monophasic OC containing 30-mcg ethinyl estradiol and 150-mcg levonorgestrel (LNG) in 17 normal-weight healthy White women and a single-dose 9-sample study of the same OC after a 1-month washout. We compared the 13-sample steady-state results with several steady-state and single-dose results calculated using parsimonious sampling schemes., Results: The 13-sample steady-state 24-h LNG AUC was highly correlated with the steady-state 24-h trough value [r=0.95; 95% confidence interval (0.85, 0.98)] and with the steady-state 6-, 8-, 12- and 16-h values (0.92≤r≤0.95). The trough values after one or two doses were moderately correlated with the steady-state 24-h AUC value [r=0.70; 95% CI (0.27, 0.90) and 0.77; 95% CI (0.40, 0.92), respectively]., Conclusions: Single time-point concentrations at steady state and after administration of one or two OCs gave highly to moderately correlated estimates of steady-state LNG AUC. Using such measures could facilitate prospective pharmaco-epidemiologic studies of the OC and its side effects., Implications: A single time-point LNG concentration at steady state is an excellent proxy for complete and resource-intensive steady-state AUC measurement. The trough level after two single doses is a fair proxy for steady-state AUC. These results provide practical tools to facilitate large studies to investigate the relationship between systemic LNG exposure and side effects in a real-life setting., (Copyright © 2017 Elsevier Inc. All rights reserved.)

The early literature and reviews have described the pharmacokinetics (PK) of oral contraceptive (OC) compounds such as ethinyl estradiol (EE) and levonorgestrel (LNG) in women as subject to large intersubject variability. This was partly due to the use of diverse radioimmunoassays, limited sampling periods and an incomplete understanding of single- vs. multiple-dose kinetics and the role of EE in causing both inhibition of hepatic metabolism along with induction of sex hormone binding globulin. Over the past two decades, LNG and EE have been used as target drugs for the assessment of possible drug interactions upon introduction of many new therapeutic agents. This has resulted in at least 17 publications that describe the PK of LNG and EE in women using various 150 mcg/30 mcg products under fairly standard multiple-dose conditions. A review of these studies indicates only moderate variability in the C max and area under the curve both within and across these studies. There is impressive similarity in these drug exposure indices found in studies carried out with several products by investigators at numerous sites and countries., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Related to concerns about the role of obesity in the efficacy of contraceptive drugs, a review of the literature was carried out in regard to the pharmacokinetics of ethinyl estradiol and various progestins given by various routes of administration. Most studies show that obese women exhibit modestly lower plasma concentrations of these drugs (circa 30%) when given the same doses as normal-weight women. While the mechanism is uncertain, precedence in the literature suggests that this is due to body weight-related differences in metabolism rates. Confusing in some of the literature is that a few studies have reported erroneously calculated pharmacokinetic parameters after multiple dosing of oral contraceptives. A demonstration of appropriate pharmacokinetic methodology is provided., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objective: To understand the potential duration of action for Liletta®, we conducted this study to estimate levonorgestrel (LNG) release rates over approximately 5½years of product use., Methods: Clinical sites in the U.S. Phase 3 study of Liletta collected the LNG intrauterine systems (IUSs) from women who discontinued the study. We randomly selected samples within 90-day intervals after discontinuation of IUS use through 900days (approximately 2.5years) and 180-day intervals for the remaining duration through 5.4years (1980days) to evaluate residual LNG content. We also performed an initial LNG content analysis using 10 randomly selected samples from a single lot. We calculated the average ex vivo release rate using the residual LNG content over the duration of the analysis., Results: We analyzed 64 samples within 90-day intervals (range 6-10 samples per interval) through 900days and 36 samples within 180-day intervals (6 samples per interval) for the remaining duration. The initial content analysis averaged 52.0±1.8mg. We calculated an average initial release rate of 19.5mcg/day that decreased to 17.0, 14.8, 12.9, 11.3 and 9.8mcg/day after 1, 2, 3, 4 and 5years, respectively. The 5-year average release rate is 14.7mcg/day., Conclusion: The estimated initial LNG release rate and gradual decay of the estimated release rate are consistent with the target design and function of the product. The calculated LNG content and release rate curves support the continued evaluation of Liletta as a contraceptive for 5 or more years of use., Implications Statement: Liletta LNG content and release rates are comparable to published data for another LNG 52-mg IUS. The release rate at 5years is more than double the published release rate at 3years with an LNG 13.5-mg IUS, suggesting continued efficacy of Liletta beyond 5years., (Copyright © 2016 Elsevier Inc. All rights reserved.)