scholarly journals Influence of the OATP Polymorphism on the Population Pharmacokinetics of Methotrexate in Chinese Patients

2019 ◽  
Vol 20 (7) ◽  
pp. 592-600 ◽  
Author(s):  
Zhiqi Wang ◽  
Nan Zhang ◽  
Chaoyang Chen ◽  
Shuqing Chen ◽  
Junyu Xu ◽  
...  

Background: The Pharmacokinetics of Methotrexate (MTX) has been reported to show significant intersubject variability. MTX is metabolized by SHMT1 and transported by OATP1B1 and OATP1B3 both of which show genetic polymorphisms. The non-genetic and genetic factors may influence the pharmacokinetics of MTX. Objective: This study aimed to determine the pharmacokinetic parameters of MTX in Chinese patients and to investigate the effect of various non-genetic factors and genetic variants of OATP1B1, OATP1B3 on MTX’s pharmacokinetics. Method: MTX concentration and clinical characteristics data were collected from 71 rheumatoid arthritis patients. For each patient, SLC19A1, SHMT1, OATP1B1, and OATP1B3 genotyping were tested. Population pharmacokinetic analysis was performed by Nonlinear Mixed-Effect Modeling (NONMEM). MTX pharmacokinetic properties analysis was executed using the one-compartment pharmacokinetic model which incorporated first-order conditional estimation methods with interaction. Besides, the impact of genetic factors and demographic factors on MTX disposition were explored. Results: All the genotypes of steady-state plasma concentrations and OATP1B1 rs4149056, OATP1B1 rs2306283, and OATP1B3 rs7311358 were determined. The detected blood drug concentration reached the standard. Genotypes were all measured. At the same time, the population pharmacokinetic model of methotrexate was obtained CL(L·h-1) =8.25× e0.167× SNP (SNP: SLCO1B1 388A/A=3; SLCO1B1 388A/G=2; SLCO1B1 388G/G=1); V(L)= 32.8; Ka(h- 1)=1.69. Conclusion: : In our study, it was showed that OATP1B1-388 G>A SNP had a significant effect on CL/F. The factor should be considered when determining MTX dosing. However, prospective studies with a large number of participants are needed to validate the results of this study.

2020 ◽  
Vol 48 (8) ◽  
pp. 030006052095228
Author(s):  
Jinlin Guo ◽  
Yayu Huo ◽  
Fang Li ◽  
Yuanping Li ◽  
Zhaojun Guo ◽  
...  

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.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 754
Author(s):  
Seung-Hyun Jeong ◽  
Ji-Hun Jang ◽  
Hea-Young Cho ◽  
Yong-Bok Lee

The aims of this study were: (1) to perform population pharmacokinetic analysis of cefaclor in healthy Korean subjects, and (2) to investigate possible effects of various covariates on pharmacokinetic parameters of cefaclor. Although cefaclor belongs to the cephalosporin family antibiotic that has been used in various indications, there have been very few population studies on factors affecting its pharmacokinetics. Therefore, this study is very important in that effective therapy could be possible through a population pharmacokinetic study that explores effective covariates related to cefaclor pharmacokinetic diversity between individuals. Pharmacokinetic results of 48 subjects with physical and biochemical parameters were used for the population pharmacokinetic analysis of cefaclor. A one-compartment with lag-time and first-order absorption/elimination was constructed as a base model and extended to include covariates that could influence between-subject variability. Creatinine clearance and body weight significantly influenced systemic clearance and distribution volume of cefaclor. Cefaclor’s final population pharmacokinetic model was validated and some of the population’s pharmacokinetic diversity could be explained. Herein, we first describe the establishment of a population pharmacokinetic model of cefaclor for healthy Koreans that might be useful for customizing cefaclor or exploring additional covariates in patients.


2018 ◽  
Author(s):  
Nilar Lwin ◽  
Zheng Liu ◽  
Mark Loewenthal ◽  
Pauline Dobson ◽  
Ji Woong Yoo ◽  
...  

Flucloxacillin, a beta-lactam antibiotic of the penicillin class, is considered first line therapy for methicillin sensitive Staphylococcus aureus (MSSA) in Australia. At our tertiary referral hospital in the home (HITH) program, it has been prescribed in a standard dosage of 8 grams per day by continuous infusion for more than 20 years. The aim of this observational study was to characterize the pharmacokinetic profile of flucloxacillin in patients who receive continuous infusion in the HITH setting, and to undertake population pharmacokinetic analysis performed with NONMEM software by comparing various structural models. This study utilised flucloxacillin concentrations from 44 separate specimens obtained from 23 patients. Twenty-five of these were collected immediately after elastomeric device removal, representing steady-state concentrations, and the remaining 19 were each collected at least 45 minutes after device removal to determine clearance of the drug. Plasma concentrations ranged from 13 to 194 mg/L with median steady-state concentration of 51.5 mg/L and inter-quartile range of 24.6 mg/L. The time-course of flucloxacillin was best described by a 1-compartment model. The best three covariates, CrCL (ΔOFV= -11.7), eGFR (ΔOFV= -5.9) and serum albumin (ΔOFV= -5.8) were found to be equivalent in terms of decreasing the OFV. CrCL was superior in explaining inter individual variability. The best model for flucloxacillin clearance was a one compartment model with CrCL as the sole covariate. The estimated population parameters were 9.5 L for volume of distribution and 8.1 L/h for flucloxacillin clearance.


2019 ◽  
Vol 104 (6) ◽  
pp. e42.2-e42
Author(s):  
Z Li ◽  
Z Jiao

The main goal of our study was to characterize the population pharmacokinetics of vancomycin in critically ill Chinese neonates to develop a pharmacokinetic model and investigate factors that have significant influences on the pharmacokinetics of vancomycin in this population.1 2 The study population consisted of 80neonates in the neonatal intensive care unit (ICU)from which 165 trough and peak concentrations of vancomycin were obtained.Nonlinear mixed effect modeling was used to develop a population pharmacokinetic model for vancomycin.4 The stability and predictive ability of the final model were evaluated based on diagnostic plots, normalized prediction distribution errorsandthe bootstrap method.Serum creatinine (Scr) and body weight were significant covariates on the clearance of vancomycin.5 6 The average clearance was 0.309L/h for a neonate with Scr of 23.3mmol/L and body weight of 2.9 kg. No obvious ethnic differences in the clearance of vancomycin were found relative to the earlier studies of Caucasian neonates. Moreover, the established model indicated that in patients with a greater renal clearance status, especially Scr < 15mmol/L,current guideline recommendationswould likely not achieve therapeuticarea under the concentration-time curve over24 h/minimum inhibitoryconcentration (AUC24h/MIC) ≥ 400.3 The exceptions to this areBritish National Formulary (2016–2017), Blue Book (2016) and Neofax (2017). Recommended dose regimensfor neonates with differentScrlevelsandpostmenstrual ageswere estimatedbased on Monte Carlo simulations andthe established model.These findings will be valuable for developing individualized dosage regimens in the neonatal ICU setting.ReferencesAbdel HO, Al OS, Nazer LH., Mubarak S, Le, J. Vancomycin pharmacokinetics and predicted dosage requirements in pediatric cancer patients. Journal of Oncology Pharmacy Practice 2015;22(3):448–453doi: 10.1177/1078155215591386Anderson, B. J., Allegaert, K., Jn, V. D. A., Cossey, V., &amp;Holford, N. H. ( 2007). Vancomycin pharmacokinetics in preterm neonates and the prediction of adult clearance. British Journal of Clinical Pharmacolog;63(1):75–84. doi: 10.1111/j.1365-2125.2006.02725.xAllegaert K, Anderson BJ, Jn, VDA, Vanhaesebrouck, S., & De, Z. F. ( 2007). Renal drug clearance in preterm neonates: relation to prenatal growth. Therapeutic Drug Monitoring, 29(3), 284–291. doi: 10.1097/FTD.0b013e31806db3f5Byon, W., Smith, M. K., Chan, P., Tortorici, M. A., Riley, S., & Dai, H., et al. ( 2013). Establishing best practices and guidance in population modeling: an experience with an internal population pharmacokinetic analysis guidance. CptPharmacometrics & Systems Pharmacology,2(7), e51. doi: 10.1016/j.cmpb.2010.04.018Capparelli, E. V., Lane, F. R., Romanowski, G. L., Pharm, M. F., Murray, W., & Sousa, P., et al. ( 2001). The influences of renal function and maturation on vancomycin elimination in newborns and infants. Journal of Clinical Pharmacology, 41(9), 927–934.Centers for Disease Control and Prevention. ( 2009). WHO Child Growth Standards. http://www.who.int/childgrowth/en. [EB/OL] 2017-09-12Disclosure(s)Nothing to disclose


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Soon Min Lee ◽  
Seungwon Yang ◽  
Soyoung Kang ◽  
Min Jung Chang

AbstractThe pharmacokinetics of vancomycin vary among neonates, and we aimed to conduct population pharmacokinetic analysis to determine the optimal dosage of vancomycin in Korean neonates. From a retrospective chart review, neonates treated with vancomycin from 2008 to 2017 in a neonatal intensive care unit (NICU) were included. Vancomycin concentrations were collected based on therapeutic drug monitoring, and other patient characteristics were gathered through electronic medical records. We applied nonlinear mixed-effect modeling to build the population pharmacokinetic model. One- and two-compartment models with first-order elimination were evaluated as potential structural pharmacokinetic models. Allometric and isometric scaling was applied to standardize pharmacokinetic parameters for clearance and volume of distribution, respectively, using fixed powers (0.75 and 1, respectively, for clearance and volume). The predictive performance of the final model was developed, and dosing strategies were explored using Monte Carlo simulations with AUC0–24 targets 400–600. The patient cohort included 207 neonates, and 900 vancomycin concentrations were analyzed. Only 37.4% of the analyzed concentrations were within trough concentrations 5–15 µg/mL. A one-compartment model with first-order elimination best described the vancomycin pharmacokinetics in neonates. Postmenstrual age (PMA) and creatinine clearance (CLcr) affected the clearance of vancomycin, and model evaluation confirmed the robustness of the final model. Population pharmacokinetic modeling and dose optimization of vancomycin in Korean neonates showed that vancomycin clearance was related to PMA and CLcr, as well as body weight. A higher dosage regimen than the typical recommendation is suggested.


2011 ◽  
Vol 16 (4) ◽  
pp. 246-261 ◽  
Author(s):  
Athena F. Zuppa ◽  
Gregory B. Hammer ◽  
Jeffrey S. Barrett ◽  
Brian F. Kenney ◽  
Nastya Kassir ◽  
...  

OBJECTIVES The administration of acetaminophen via the oral and rectal routes may be contraindicated in specific clinical settings. Intravenous administration provides an alternative route for fever reduction and analgesia. This phase 1 study of intravenous acetaminophen (Ofirmev, Cadence Pharmaceuticals, Inc., San Diego, CA) in inpatient pediatric patients with pain or fever requiring intravenous therapy was designed to assess the safety and pharmacokinetics of repeated doses over 48 hours. METHODS Neonates (full-term to 28 days) received either 12.5 mg/kg every 6 hours or 15 mg/kg every 8 hours. Infants (29 days to &lt;2 years), children (2 to &lt;12 years) and adolescents (≥12 years) received either 12.5 mg/kg every 4 hours or 15 mg/kg every 6 hours. Both noncompartmental and population nonlinear mixed-effects modeling approaches were used. Urinary metabolite data were analyzed, and safety and tolerability were assessed. RESULTS Pharmacokinetic parameters of acetaminophen were estimated using a two-compartment disposition model with weight allometrically expressed on clearances and central and peripheral volumes of distribution (Vds). Postnatal age, with a maturation function, was a significant covariate on clearance. Total systemic normalized clearance was 18.4 L/hr per 70 kg, with a plateau reached at approximately 2 years. Total central and peripheral Vds of acetaminophen were 16 and 59.5 L/70 kg, respectively. The drug was well tolerated based on the incidence of adverse events. The primary and minor pathways of elimination were acetaminophen glucuronidation, sulfation, and glutathione conjugate metabolites across all age groups. CONCLUSIONS Intravenous acetaminophen in infants, children, and adolescents was well tolerated and achieved plasma concentrations similar to those achieved with labeled 15 mg/kg body weight doses by oral or rectal administration.


2006 ◽  
Vol 50 (11) ◽  
pp. 3754-3762 ◽  
Author(s):  
Yusuke Tanigawara ◽  
Reiko Sato ◽  
Kunihiko Morita ◽  
Mitsuo Kaku ◽  
Naoki Aikawa ◽  
...  

ABSTRACT Arbekacin, a derivative of dibekacin, is an aminoglycoside developed and widely used in Japan for the treatment of patients infected with methicillin-resistant Staphylococcus aureus (MRSA). The population pharmacokinetics of arbekacin was investigated in the Japanese, using 353 patients infected with MRSA and 50 healthy or renally impaired volunteers. The age of the study population ranged from 8 to 95 years, and weight ranged from 10.8 to 107 kg. In total, 1,581 serum arbekacin concentrations were measured (primarily from routine patient care) and used to perform the present pharmacokinetic analysis. Drug concentration-time data were well described by a two-compartment open model. Factors influencing arbekacin pharmacokinetics were investigated using a nonlinear mixed-effect model analysis. The best-developed model showed that drug clearance (CL) was related to creatinine clearance (CLCR), age, and body weight (WT), as expressed by CL (liter/h) = 0.0319CLCR + (26.5/age) (CLCR < 80 ml/min) and CL (liter/h) = 0.0130 CLCR + 0.0342WT + (26.5/age) (CLCR ≥ 80 ml/min). The volume of distribution for the central and peripheral compartments was different in healthy subjects and infected patients, and this difference was more pronounced among disease types. The elderly subjects (aged 80 years or over) exhibited, on average, a 19% greater volume for the central compartment. The volumes for the peripheral compartment were 50.6 liters in patients with pneumonia and 24.3 liters in patients with sepsis. The population pharmacokinetic parameters of arbekacin obtained here are useful for optimal use of this aminoglycoside in the treatment of MRSA-infected patients.


2018 ◽  
Vol 62 (7) ◽  
Author(s):  
Marlou L. P. S. van Iersel ◽  
Stefaan Rossenu ◽  
Rik de Greef ◽  
Hetty Waskin

ABSTRACT A delayed-release solid tablet formulation that releases posaconazole in the small intestine was developed to maximize systemic absorption. This study aimed to characterize the pharmacokinetics of the posaconazole solid tablet formulation in adult subjects and to investigate the potential impact of demographic and clinical factors on posaconazole exposure through a population pharmacokinetic approach. Nonlinear mixed-effects modeling was performed using data from several studies conducted in healthy volunteers and patients. The influence of demographic and clinical factors on pharmacokinetic parameters was evaluated using a stepwise forward inclusion/backward exclusion procedure. The final pharmacokinetic model was used to simulate posaconazole exposure in patients at high risk for invasive fungal diseases treated with the proposed posaconazole dose of 300 mg twice daily on day 1, followed by 300 mg daily for 27 days. A one-compartment pharmacokinetic model with sequential zero-order and first-order absorption and a first-order disposition from the central compartment adequately described the pharmacokinetic profile of the posaconazole solid tablet formulation. Significant covariates included disease state (acute myeloid leukemia/myelodysplasia versus allogeneic hematopoietic stem cell transplantation), body weight, and formulation on bioavailability; food status on first-order absorption rate; and dosing regimen (a single dose versus multiple doses) on clearance. Except for body weight, the impact of these covariates on posaconazole exposure was considered clinically irrelevant. This population pharmacokinetic analysis confirmed that the proposed dose of the posaconazole solid tablet formulation provides adequate target therapeutic exposure (>0.5 mg/liter) to a broad range of patients at high risk for invasive fungal disease.


2000 ◽  
Vol 18 (12) ◽  
pp. 2459-2467 ◽  
Author(s):  
James M. Gallo ◽  
Paul B. Laub ◽  
Eric K. Rowinsky ◽  
Louise B. Grochow ◽  
Sharyn D. Baker

PURPOSE: To characterize the pharmacokinetics of topotecan in a population model that would identify patient variables or covariates that appreciably impacted on its disposition. PATIENTS AND METHODS: All data were collected from 82 patients entered in four different phase I trials that were previously reported as separate studies from 1992 to 1996. All patients received topotecan as a 30-minute constant-rate infusion on a daily-times-five schedule and were selected for this study because their daily dose did not exceed 2.0 mg/m2. Among the 82 patients were 30 patients classified as having renal insufficiency and 13 patients with hepatic dysfunction. The population pharmacokinetic model was built in sequential manner, starting with a covariate-free model and progressing to a covariate model with the aid of generalized additive modeling. RESULTS: A linear two-compartment model characterized total topotecan plasma concentrations (n = 899). Four primary pharmacokinetic parameters (total clearance, volume of the central compartment, distributional clearance, and volume of the peripheral compartment) were related to various combinations of covariates. The relationship for total clearance (TVCL [L/h] = 32.0 + [0.356(WT − 71) + 0.308(HT − 168.5) − 8.42(SCR − 1.1)] × [1 + 0.671 sex]) was dependent on the patients’ weight (WT), height (HT), serum creatinine (SCR), and sex and had a moderate ability to predict (r2 = 0.64) each patient’s individual clearance value. The addition of covariates to the population model improved the prediction errors, particularly for clearance. Removal of 10 outlying patients from the analysis improved the ability of the model to predict individual clearance values (r2 = 0.77). CONCLUSION: A population pharmacokinetic model for total topotecan has been developed that incorporates measures of body size and renal function to predict total clearance. The model can be used prospectively to obtain a revised and validated model that can then be used to design individualized dosing regimens.


2017 ◽  
Vol 61 (3) ◽  
Author(s):  
Ashley M. Hopkins ◽  
Jessica Wojciechowski ◽  
Ahmad Y. Abuhelwa ◽  
Stuart Mudge ◽  
Richard N. Upton ◽  
...  

ABSTRACT The literature presently lacks a population pharmacokinetic analysis of doxycycline. This study aimed to develop a population pharmacokinetic model of doxycycline plasma concentrations that could be used to assess the power of bioequivalence between Doryx delayed-release tablets and Doryx MPC. Doxycycline pharmacokinetic data were available from eight phase 1 clinical trials following single/multiple doses of conventional-release doxycycline capsules, Doryx delayed-release tablets, and Doryx MPC under fed and fasted conditions. A population pharmacokinetic model was developed in a stepwise manner using NONMEM, version 7.3. The final covariate model was developed according to a forward inclusion (P < 0.01) and then backward deletion (P < 0.001) procedure. The final model was a two-compartment model with two-transit absorption compartments. Structural covariates in the base model included formulation effects on relative bioavailability (F), absorption lag (ALAG), and the transit absorption rate (KTR) under the fed status. An absorption delay (lag) for the fed status (FTLAG2 = 0.203 h) was also included in the model as a structural covariate. The fed status was observed to decrease F by 10.5%, and the effect of female sex was a 14.4% increase in clearance. The manuscript presents the first population pharmacokinetic model of doxycycline plasma concentrations following oral doxycycline administration. The model was used to assess the power of bioequivalence between Doryx delayed-release tablets and Doryx MPC, and it could potentially be used to critically examine and optimize doxycycline dose regimens.


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