scholarly journals Population Pharmacokinetic Analysis of Yimitasvir in Chinese Healthy Volunteers and Patients With Chronic Hepatitis C Virus Infection

2021 ◽  
Vol 11 ◽  
Author(s):  
Xiao-duo Guan ◽  
Xian-ge Tang ◽  
Ying-jun Zhang ◽  
Hong-ming Xie ◽  
Lin Luo ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Healthy Volunteers ◽  
Population Pharmacokinetic Model ◽  
Pharmacokinetic Model ◽  
Population Pharmacokinetic ◽  
Oral Clearance ◽  
First Order ◽  
Apparent Oral Clearance ◽  
Significant Covariates

Yimitasvir is a novel, oral hepatitis C virus (HCV) non-structural protein 5A inhibitor for the treatment of chronic HCV genotype 1 infection. The objective of this analysis was to develop a population pharmacokinetic model of yimitasvir in Chinese healthy volunteers and HCV infection patients. The model was performed using data from 219 subjects across six studies. Nonlinear mixed effects models were developed using Phoenix NLME software. The covariates were evaluated using a stepwise forward inclusion (p < 0.01) and then a backward exclusion procedure (p < 0.001). A two-compartment model with sequential zero-first order absorption and first-order elimination reasonably described yimitasvir pharmacokinetics (PK). The apparent oral clearance and central volume of distribution were 13.8 l·h−1 and 188 l, respectively. The bioavailability (F) of yimitasvir decreased 12.9% for each 100 mg dose increase. Food was found to affect absorption rate (Ka) and F. High-fat meal decreased Ka and F by 90.9% and 38.5%, respectively. Gender and alanine aminotransferase were identified as significant covariates on apparent oral clearance. Female subjects had lower clearance than male subjects. Zero-order absorption duration was longer in healthy volunteers (2.17 h) than that in patients (1.43 h). The population pharmacokinetic model described yimitasvir PK profile well. Food decreased Ka and F significantly, so it was recommended to take yimitasvir at least 2 h before or after a meal. Other significant covariates were not clinically important.

scholarly journals Pharmacokinetic Modeling and Limited Sampling Strategies Based on Healthy Volunteers for Monitoring of Ertapenem in Patients with Multidrug-Resistant Tuberculosis

2017 ◽  
Vol 61 (4) ◽  
Author(s):  
S. P. van Rijn ◽  
M. A. Zuur ◽  
R. van Altena ◽  
O. W. Akkerman ◽  
J. H. Proost ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Population Pharmacokinetic Model ◽  
Pharmacokinetic Model ◽  
Sampling Strategy ◽  
Free Fraction ◽  
Limited Sampling Strategy ◽  
Population Pharmacokinetic ◽  
Time Curve ◽  
Limited Sampling ◽  
Mdr Tb

ABSTRACT Ertapenem is a broad-spectrum carbapenem antibiotic whose activity against Mycobacterium tuberculosis is being explored. Carbapenems have antibacterial activity when the plasma concentration exceeds the MIC at least 40% of the time (40% T MIC). To assess the 40% T MIC in multidrug-resistant tuberculosis (MDR-TB) patients, a limited sampling strategy was developed using a population pharmacokinetic model based on data for healthy volunteers. A two-compartment population pharmacokinetic model was developed with data for 42 healthy volunteers using an iterative two-stage Bayesian method. External validation was performed by Bayesian fitting of the model developed with data for volunteers to the data for individual MDR-TB patients (in which the fitted values of the area under the concentration-time curve from 0 to 24 h [AUC0–24, fit values] were used) using the population model developed for volunteers as a prior. A Monte Carlo simulation (n = 1,000) was used to evaluate limited sampling strategies. Additionally, the 40% T MIC with the free fraction (f 40% T MIC) of ertapenem in MDR-TB patients was estimated with the population pharmacokinetic model. The population pharmacokinetic model that was developed was shown to overestimate the area under the concentration-time curve from 0 to 24 h (AUC0–24) in MDR-TB patients by 6.8% (range, −17.2 to 30.7%). The best-performing limited sampling strategy, which had a time restriction of 0 to 6 h, was found to be sampling at 1 and 5 h (r 2 = 0.78, mean prediction error = −0.33%, root mean square error = 5.5%). Drug exposure was overestimated by a mean percentage of 4.2% (range, −15.2 to 23.6%). When a free fraction of 5% was considered and the MIC was set at 0.5 mg/liter, the minimum f 40% T MIC would have been exceeded in 9 out of 12 patients. A population pharmacokinetic model and limited sampling strategy, developed using data from healthy volunteers, were shown to be adequate to predict ertapenem exposure in MDR-TB patients.

scholarly journals Application of Population Pharmacokinetic Analysis to Characterize CYP2C19 Mediated Metabolic Mechanism of Voriconazole and Support Dose Optimization

2022 ◽  
Vol 12 ◽  
Author(s):  
SiChan Li ◽  
SanLan Wu ◽  
WeiJing Gong ◽  
Peng Cao ◽  
Xin Chen ◽  
...  
Keyword(s):  
Maintenance Dose ◽  
Population Pharmacokinetic Model ◽  
Pharmacokinetic Model ◽  
Compartment Model ◽  
Population Pharmacokinetic Analysis ◽  
Pharmacokinetic Analysis ◽  
Population Pharmacokinetic ◽  
Immunocompromised Patients ◽  
First Order ◽  
Dosing Regimens

Purpose: The aims of this study were to establish a joint population pharmacokinetic model for voriconazole and its N-oxide metabolite in immunocompromised patients, to determine the extent to which the CYP2C19 genetic polymorphisms influenced the pharmacokinetic parameters, and to evaluate and optimize the dosing regimens using a simulating approach.Methods: A population pharmacokinetic analysis was conducted using the Phoenix NLME software based on 427 plasma concentrations from 78 patients receiving multiple oral doses of voriconazole (200 mg twice daily). The final model was assessed by goodness of fit plots, non-parametric bootstrap method, and visual predictive check. Monte Carlo simulations were carried out to evaluate and optimize the dosing regimens.Results: A one-compartment model with first-order absorption and mixed linear and concentration-dependent-nonlinear elimination fitted well to concentration-time profile of voriconazole, while one-compartment model with first-order elimination well described the disposition of voriconazole N-oxide. Covariate analysis indicated that voriconazole pharmacokinetics was substantially influenced by the CYP2C19 genetic variations. Simulations showed that the recommended maintenance dose regimen would lead to subtherapeutic levels in patients with different CYP2C19 genotypes, and elevated daily doses of voriconazole might be required to attain the therapeutic range.Conclusions: The joint population pharmacokinetic model successfully characterized the pharmacokinetics of voriconazole and its N-oxide metabolite in immunocompromised patients. The proposed maintenance dose regimens could provide a rationale for dosage individualization to improve clinical outcomes and minimize drug-related toxicities.

scholarly journals Population Pharmacokinetic Modeling of Plasma and Intracellular Ribavirin Concentrations in Patients with Chronic Hepatitis C Virus Infection

2015 ◽  
Vol 59 (4) ◽  
pp. 2179-2188 ◽  
Author(s):  
Liviawati S. Wu ◽  
Joseph E. Rower ◽  
James R. Burton ◽  
Peter L. Anderson ◽  
Kyle P. Hammond ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Mononuclear Cells ◽  
Formation Rate ◽  
Plasma Concentrations ◽  
Compartment Model ◽  
Population Pharmacokinetic ◽  
Peripheral Blood Mononuclear ◽  
First Order

ABSTRACTRibavirin, a guanosine analog, is a broad-spectrum antiviral agent. Ribavirin has been a fundamental component of the treatment of hepatitis C virus (HCV) infection for decades, but there is a very limited understanding of the clinical pharmacology of this drug. Furthermore, it is associated with a major dose-limiting toxicity, hemolytic anemia. Ribavirin undergoes intracellular phosphorylation by host enzymes to ribavirin monophosphate (RMP), ribavirin diphosphate (RDP), and ribavirin triphosphate (RTP). The intracellular forms have been associated with antiviral and toxic effectsin vitro, but the kinetics of these phosphorylated moieties have not been fully elucidatedin vivo. We developed a model to characterize the plasma pharmacokinetics of ribavirin and the difference between intracellular phosphorylation kinetics in red cells (nonnucleated) and in peripheral blood mononuclear cells (nucleated). A time-independent two-compartment model with first-order absorption described the plasma data well. The cellular phosphorylation kinetics was described by a one-compartment model for RMP, with the formation rate driven by plasma concentrations and the first-order degradation rate. RDP and RTP rapidly reached equilibrium with RMP. Concomitant telaprevir use, inosine triphosphatase genetics, creatinine clearance, weight, and sex were significant covariates. The terminal ribavirin half-life in plasma and phosphorylated anabolites in cells was approximately 224 h. We found no evidence of time-dependent kinetics. These data provide a foundation for uncovering concentration-effect associations for ribavirin and determining the optimal dose and duration of this drug for use in combination with newer direct-acting HCV agents. (This study has been registered at ClinicalTrials.gov under registration no. NCT01097395.)

scholarly journals Impact of gender, albumin, and CYP2C19 polymorphisms on valproic acid in Chinese patients: a population pharmacokinetic model

2020 ◽  
Vol 48 (8) ◽  
pp. 030006052095228
Author(s):  
Jinlin Guo ◽  
Yayu Huo ◽  
Fang Li ◽  
Yuanping Li ◽  
Zhaojun Guo ◽  
...  
Keyword(s):  
Valproic Acid ◽  
Population Pharmacokinetic Model ◽  
Pharmacokinetic Model ◽  
Volume Of Distribution ◽  
Chinese Patients ◽  
Population Pharmacokinetic ◽  
Pharmacokinetic Data ◽  
Mixed Effect ◽  
First Order ◽  
The Impact

Objective This prospective study aimed to establish the valproic acid (VPA) population pharmacokinetic model in Chinese patients and realise personalised medication on the basis of population pharmacokinetics. Methods The patients’ clinical information and VPA plasma concentrations were collected from The General Hospital of Taiyuan Iron & Steel (Group) Corporation (TISCO). Nonlinear mixed-effect modelling was used to build the population pharmacokinetic model. To characterise the pharmacokinetic data, a one-compartment pharmacokinetic model with first-order absorption and elimination was used. The first-order conditional estimation with η-ε interaction was applied throughout the model-developing procedure. The absorption rate constant (Ka) was fixed at 2.38 hour−1, and the impact of covariates on clearance and apparent volume of distribution were also explored. Medical records of 60 inpatients were reviewed prospectively and the objective function value (OFV) of the base model and final model were 851.813 and 817.622, respectively. Results Gender was identified as the covariate that had a significant impact on the volume of distribution, and albumin and CYP2C19 genotypes influenced clearance. Conclusion Bootstrap and VPC indicated that a reliable model had been developed that was based on the simulation results, and a simple-to-use dosage regimen table was created to guide clinicians for VPA drug dosing.

scholarly journals Effect of Pregnancy on Unbound Raltegravir Concentrations in the ANRS 160 RalFe Trial

2020 ◽  
Vol 64 (10) ◽  
Author(s):  
Yi Zheng ◽  
Déborah Hirt ◽  
Sandrine Delmas ◽  
Gabrielle Lui ◽  
Sihem Benaboud ◽  
...  
Keyword(s):  
Population Pharmacokinetic Model ◽  
Pharmacokinetic Model ◽  
Area Under The Curve ◽  
Compartment Model ◽  
Population Pharmacokinetic ◽  
Third Trimester ◽  
Open Label ◽  
First Order ◽  
The Third ◽  
Pregnancy And Postpartum

ABSTRACT A population pharmacokinetic model was developed to explore the pharmacokinetics modification of unbound raltegravir during pregnancy. The RalFe ANRS160 study was a nonrandomized, open-label, multicenter trial enrolling HIV-infected pregnant women receiving a combined antiretroviral regimen containing 400 mg raltegravir twice daily. Biological samples were collected during the third trimester of pregnancy (between 30 and 37 weeks of gestational age) and at postpartum (4 to 6 weeks after delivery). A population pharmacokinetic model was developed with Monolix software. A total of 360 plasma samples were collected from 43 women during pregnancy and postpartum. The unbound raltegravir was described by a one-compartment model with a transit compartment with first-order absorption, evolving to bound raltegravir (by a linear binding to albumin) or metabolism to RAL-glucuronide or to a first-order elimination, with a circadian rhythm. During pregnancy, the absorption was decreased and delayed and the raltegravir elimination clearance and glucuronidation increased by 37%. Median total and unbound area under the curve from 0 to 12 h significantly decreased by 36% and 27% during pregnancy. Median total trough concentration (Ctrough) decreased significantly in the evening (28%); however, the median total Ctrough in the morning, unbound Ctrough in the morning, and unbound Ctrough in the evening showed a nonsignificant decrease of 16%, 1%, and 15%, respectively, during pregnancy compared to the postpartum period. This is the first study reporting the pharmacokinetics of unbound raltegravir during pregnancy. As unbound Ctrough did not significantly decrease during the third trimester, the pregnancy effect on raltegravir unbound concentrations was not considered clinically relevant. (This study has been registered at ClinicalTrials.gov under identifier NCT02099474.)

scholarly journals Population Pharmacokinetic Modeling To Estimate the Contributions of Genetic and Nongenetic Factors to Efavirenz Disposition

2016 ◽  
Vol 61 (1) ◽  
Author(s):  
Jason D. Robarge ◽  
Ingrid F. Metzger ◽  
Jessica Lu ◽  
Nancy Thong ◽  
Todd C. Skaar ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
Fat Mass ◽  
Pharmacokinetic Model ◽  
Structural Model ◽  
Fat Free Mass ◽  
Additional Patient ◽  
Population Pharmacokinetic ◽  
Oral Clearance ◽  
Apparent Oral Clearance

ABSTRACT Efavirenz pharmacokinetics is characterized by large between-subject variability, which determines both therapeutic response and adverse effects. Some of the variability in efavirenz pharmacokinetics has been attributed to genetic variability in cytochrome P450 genes that alter efavirenz metabolism, such as CYP2B6 and CYP2A6. While the effects of additional patient factors have been studied, such as sex, weight, and body mass index, the extent to which they contribute to variability in efavirenz exposure is inconsistently reported. The aim of this analysis was to develop a pharmacometric model to quantify the contribution of genetic and nongenetic factors to efavirenz pharmacokinetics. A population-based pharmacokinetic model was developed using 1,132 plasma efavirenz concentrations obtained from 73 HIV-seronegative volunteers administered a single oral dose of 600 mg efavirenz. A two-compartment structural model with absorption occurring by zero- and first-order processes described the data. Allometric scaling adequately described the relationship between fat-free mass and apparent oral clearance, as well as fat mass and apparent peripheral volume of distribution. Inclusion of fat-free mass and fat mass in the model mechanistically accounted for correlation between these disposition parameters and sex, weight, and body mass index. Apparent oral clearance of efavirenz was reduced by 25% and 51% in subjects predicted to have intermediate and slow CYP2B6 metabolizer status, respectively. The final pharmacokinetic model accounting for fat-free mass, fat mass, and CYP2B6 metabolizer status was consistent with known mechanisms of efavirenz disposition, efavirenz physiochemical properties, and pharmacokinetic theory. (This study has been registered at ClinicalTrials.gov under identifier NCT00668395.)

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