Prospective evaluation of a developed S-1 dosage formula based on renal function.

2019 ◽  
Vol 37 (4_suppl) ◽  
pp. 86-86
Author(s):  
Takuro Mizukami ◽  
Masashi Takeuchi ◽  
Chiyo K. Imamura ◽  
Eisuke Booka ◽  
HIROYA TAKEUCHI ◽  
...  
Keyword(s):  
Renal Function ◽  
Population Pharmacokinetic Analysis ◽  
Pharmacokinetic Analysis ◽  
Population Pharmacokinetic ◽  
Pharmacokinetic Data ◽  
Target Area ◽  
Time Curve ◽  
And Gender ◽  
A Prospective Study ◽  
Clinical Trial Information

86 Background: S-1 is an oral anticancer drug, containing tegafur (a prodrug of 5-FU), 5-chloro-2,4-dihydroxypyridine (CDHP, inhibitor of dihydoropyrimidine dehydrogenase) and potassium oxonate. Because CDHP is excreted in urine, renal dysfunction increases incidence of severe adverse drug reactions due to higher exposure of 5-FU. As approved dose of S-1 is determined by body surface area (BSA) for patients with normal renal function, dose of S-1 is practically reduced according to renal function of creatinine clearance (CLcr) estimated by the Cockcroft-Gault equation. In a previous pharmacokinetic study (n = 16), we had developed an S-1 dosage formula based on renal function achieving the target area under the concentration-time curve (AUC) of 5-FU: Dose = target AUC x (21.9 + 0.375 x CLcr) x BSA. We conducted a prospective study to evaluate and refine this formula if necessary. Methods: Thirty patients with various renal function received S-1 at dose determined by our developed formula. A series of blood samples were obtained at predefined times after the first dose to calculate the AUC of 5-FU. Predictability of the formula was evaluated by comparison between the observed and the target AUCs. Results: The observed daily AUC was ranged from 712.6 to 2868.7 ng‧h/mL in 30 patients with BSA in the range of 1.14-1.84 m2 and CLcr in the range of 23.8-96.4 mL/min. Eighteen patients of them achieved the target AUC (1447.8 ± 545.4 ng‧h/mL). Since population pharmacokinetic analysis using combined pharmacokinetic data of 30 patients in this study and 16 patients in the previous study demonstrated that clearance of 5-FU is significantly lower in female than in male, the S-1 dosage formula was refined including gender as an additional factor: Dose = target AUC × (14.5 + 8.23 x GENDER [0 for female and 1 for male] + 0.301 × CLcr) × BSA. Revised nomograms showing recommended daily dose of S-1 were proposed for males and females taking into account tablet strengths. Conclusions: The refined formula for determining S-1 dosage on the basis of renal function, BSA and gender can be applied to clinical practice to ensure efficacy and safety for cancer patients treated with S-1. Clinical trial information: UMIN 000023880.

scholarly journals Pooled Population Pharmacokinetic Analysis of Tribendimidine for the Treatment of Opisthorchis viverrini Infections

2019 ◽  
Vol 63 (4) ◽  
Author(s):  
Isabel Meister ◽  
Piyanan Assawasuwannakit ◽  
Fiona Vanobberghen ◽  
Melissa A. Penny ◽  
Peter Odermatt ◽  
...  
Keyword(s):  
Population Pharmacokinetic Analysis ◽  
Opisthorchis Viverrini ◽  
Pharmacokinetic Analysis ◽  
Population Pharmacokinetic ◽  
Pharmacokinetic Data ◽  
Therapeutic Success ◽  
Time Curve ◽  
Content Type ◽  
Mixed Effects Modeling ◽  
Younger Age

ABSTRACT Opisthorchiasis, caused by the foodborne trematode Opisthorchis viverrini, affects more than 8 million people in Southeast Asia. In the framework of a phase 2b clinical trial conducted in Lao People’s Democratic Republic, pharmacokinetic samples were obtained from 125 adult and adolescent O. viverrini-infected patients treated with 400 mg tribendimidine following the design of a sparse sampling scheme at 20 min and 2, 7.75, 8, and 30 h after treatment using dried blood spot sampling. Pharmacokinetic data for the metabolites deacetylated amidantel (dADT) and acetylated dADT (adADT) were pooled with data from two previous ascending-dose trials and evaluated using nonlinear mixed-effects modeling. The observed pharmacokinetic data were described using a flexible transit absorption model for the active metabolite dADT, followed by one-compartment disposition models for both metabolites. Significant covariates were age, body weight, formulation, and breaking of the enteric coating on the tablets. There were significant associations between O. viverrini cure and both the dADT maximum concentration and the area under the concentration-time curve (P < 0.001), with younger age being associated with a higher probability of cure. Modeling and simulation of exposures in patients with different weight and age combinations showed that an oral single dose of 400 mg tribendimidine attained therapeutic success in over 90% of adult patients. Our data confirmed that tribendimidine could be a valuable novel alternative to the standard treatment, praziquantel, for the treatment of O. viverrini infections.

scholarly journals Pyrimethamine pharmacokinetics in human immunodeficiency virus-positive patients seropositive for Toxoplasma gondii.

1996 ◽  
Vol 40 (6) ◽  
pp. 1360-1365 ◽  
Author(s):  
J M Jacobson ◽  
M Davidian ◽  
P M Rainey ◽  
R Hafner ◽  
R H Raasch ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Toxoplasma Gondii ◽  
Drug Users ◽  
Compartment Model ◽  
Population Pharmacokinetic Analysis ◽  
Pharmacokinetic Analysis ◽  
Pharmacokinetic Parameters ◽  
Population Pharmacokinetic ◽  
Time Curve ◽  
Immunodeficiency Virus

Pyrimethamine pharmacokinetics were studied in 11 human immunodeficiency virus (HIV)-positive patients who were seropositive for exposure to Toxoplasma gondii and were taking zidovudine (AIDS Clinical Trials Group Protocol 102). Pyrimethamine was administered at 50 mg daily for 3 weeks to achieve steady state, and pharmacokinetic profiles were determined after administration of the last dose. Noncompartmental and compartmental analyses were performed. Population pharmacokinetic analysis assuming a one-compartment model yielded the following estimates: area under the 24-h concentration-time curve, 42.7 +/- 12.3 micrograms.h/ml; halflife, 139 +/- 34 h; clearance, 1.28 +/- 0.41 liters/h; volume of distribution, 246 +/- 641; and absorption rate constant, 1.5 +/- 1.3 liters/h. These values are similar to those seen in subjects without HIV infection. Pyrimethamine pharmacokinetics did not differ significantly in those subjects who were intravenous drug users. Adverse effects were noted in 73% of those initially enrolled in this study, leading to discontinuation for 38%. No association was noted between pyrimethamine levels and the incidence of adverse events. No significant differences were seen in zidovudine pharmacokinetic parameters obtained from studies performed before and during treatment with pyrimethamine. In summary, pyrimethamine exhibited pharmacokinetics in HIV-infected patients that were similar to those in non-HIV-infected subjects and it did not alter the pharmacokinetics of zidovudine in these patients.

scholarly journals Population Pharmacokinetic Assessment of Vancomycin Dosing in the Large Pediatric Patient

2019 ◽  
Vol 63 (4) ◽  
Author(s):  
Brady S. Moffett ◽  
Vijay Ivaturi ◽  
Jennifer Morris ◽  
Ayse Akcan Arikan ◽  
Ankhi Dutta
Keyword(s):  
Pediatric Patients ◽  
Population Pharmacokinetic Analysis ◽  
Fat Free Mass ◽  
Pharmacokinetic Analysis ◽  
Population Pharmacokinetic ◽  
Kidney Dysfunction ◽  
Time Curve ◽  
Concentration Time ◽  
Pharmacokinetic Assessment ◽  
Dosing Strategy

ABSTRACT The most appropriate vancomycin dosing strategy in pediatric patients weighing ≥70 kg (weight based versus non-weight based) to achieve an area under the concentration-time curve (AUC) of ≥400 mg·liter/h and a trough concentration of <20 mg/liter is not known. Population pharmacokinetic analysis determined that dosing of vancomycin should be weight based using fat-free mass, with appropriate adjustment for kidney dysfunction.

scholarly journals Integrated Population Pharmacokinetic Analysis of Voriconazole in Children, Adolescents, and Adults

2012 ◽  
Vol 56 (6) ◽  
pp. 3032-3042 ◽  
Author(s):  
Lena E. Friberg ◽  
Patanjali Ravva ◽  
Mats O. Karlsson ◽  
Ping Liu
Keyword(s):  
Pediatric Population ◽  
Compartment Model ◽  
Population Pharmacokinetic Analysis ◽  
Pharmacokinetic Analysis ◽  
Population Pharmacokinetic ◽  
Parameter Estimates ◽  
Loading Dose ◽  
Time Curve ◽  
Individual Parameter ◽  
Dosing Regimens

ABSTRACTTo further optimize the voriconazole dosing in the pediatric population, a population pharmacokinetic analysis was conducted on pooled data from 112 immunocompromised children (2 to <12 years), 26 immunocompromised adolescents (12 to <17 years), and 35 healthy adults. Different maintenance doses (i.e., 3, 4, 6, 7, and 8 mg/kg of body weight intravenously [i.v.] every 12 h [q12h]; 4 mg/kg, 6 mg/kg, and 200 mg orally q12h) were evaluated in these children. The adult dosing regimens (6 mg/kg i.v. q12h on day 1, followed by 4 mg/kg i.v. q12h, and 300 mg orally q12h) were evaluated in the adolescents. A two-compartment model with first-order absorption and mixed linear and nonlinear (Michaelis-Menten) elimination adequately described the voriconazole data. Larger interindividual variability was observed in pediatric subjects than in adults. Deterministic simulations based on individual parameter estimates from the final model revealed the following. The predicted total exposure (area under the concentration-time curve from 0 to 12 h [AUC0-12]) in children following a 9-mg/kg i.v. loading dose was comparable to that in adults following a 6-mg/kg i.v. loading dose. The predicted AUC0-12s in children following 4 and 8 mg/kg i.v. q12h were comparable to those in adults following 3 and 4 mg/kg i.v. q12h, respectively. The predicted AUC0-12in children following 9 mg/kg (maximum, 350 mg) orally q12h was comparable to that in adults following 200 mg orally q12h. To achieve voriconazole exposures comparable to those of adults, dosing in 12- to 14-year-old adolescents depends on their weight: they should be dosed like children if their weight is <50 kg and dosed like adults if their weight is ≥50 kg. Other adolescents should be dosed like adults.

scholarly journals Population Pharmacokinetics of Vancomycin in the Pediatric Cardiac Surgical Population

2019 ◽  
Vol 24 (2) ◽  
pp. 107-116 ◽  
Author(s):  
Brady S. Moffett ◽  
Karla Resendiz ◽  
Jennifer Morris ◽  
Ayse Akcan-Arikan ◽  
Paul A. Checchia
Keyword(s):  
Serum Concentration ◽  
Creatinine Clearance ◽  
Cardiac Surgical Procedures ◽  
Population Pharmacokinetic Analysis ◽  
Pharmacokinetic Analysis ◽  
Population Pharmacokinetic ◽  
Pharmacokinetic Data ◽  
Population Pharmacokinetic Study ◽  
Postmenstrual Age ◽  
Dosing Strategy

OBJECTIVE Vancomycin is often used in the pediatric cardiac surgical population, but few pharmacokinetic data are available to guide dosing. METHODS A retrospective, population pharmacokinetic study was performed for patients &lt;19 years of age initiated on vancomycin after cardiac surgery in the cardiac intensive care unit from 2011–2016 in our institution. Patient data were summarized by using descriptive statistical methods, and population pharmacokinetic analysis was performed by using NONMEM. Simulation was performed to determine a dosing strategy that most frequently obtained an AUC0–24:MIC (minimum inhibitory concentration) ratio of &gt;400. RESULTS A total of 261 patients (281 cardiac surgical procedures, cardiopulmonary bypass 82.3%) met inclusion criteria (60.1% male, median age 0.31 [IQR, 0.07–0.77] years). Vancomycin (14.5 ± 1.7 mg/kg/dose) was administered at median postoperative day 9 (IQR, 4–14), with a mean serum concentration of 11.5 ± 5.5 mg/L at 8.9 ± 3.8 hours after a dose. Population pharmacokinetic analysis demonstrated that a 1-compartment proportional error model with allometrically scaled weight best fit the data, with creatinine clearance and postmenstrual age as significant covariates. Simulation identified that a dosing regimen of 20 mg/kg/dose every 8 hours was most likely to achieve an AUC0–24:MIC ratio &gt; 400 at a mean trough serum concentration of 12.9 ± 3.2 mg/L. CONCLUSIONS Vancomycin dosing in the postoperative pediatric cardiac surgical population should incorporate postmenstrual age and creatinine clearance. A vancomycin dose of 20 mg/kg every 8 hours is a reasonable empiric strategy.

scholarly journals Population Pharmacokinetic Analysis of Pazopanib in Patients and Determination of Target AUC

2021 ◽  
Vol 14 (9) ◽  
pp. 927
Author(s):  
Agustos Cetin Ozbey ◽  
David Combarel ◽  
Vianney Poinsignon ◽  
Christine Lovera ◽  
Esma Saada ◽  
...  
Keyword(s):  
Kinase Inhibitor ◽  
Plasma Concentrations ◽  
Area Under The Curve ◽  
Daily Practice ◽  
Population Pharmacokinetic Analysis ◽  
Pharmacokinetic Analysis ◽  
Therapeutic Drug ◽  
Population Pharmacokinetic ◽  
Study Phase ◽  
Target Area

Pazopanib is a potent multi-targeted kinase inhibitor approved for the treatment of advanced renal cell carcinoma and soft tissue sarcoma. The pharmacokinetics of pazopanib is characterized by a significant inter- and intra-patient variability and a target through plasma concentration of 20.5 mg·L−1. However, routine monitoring of trough plasma concentrations at fixed hours is difficult in daily practice. Herein, we aimed to characterize the pharmacokinetic (PK) profile of pazopanib and to identify a target area under the curve (AUC) more easily extrapolated from blood samples obtained at various timings after drug intake. A population pharmacokinetic (popPK) model was constructed to analyze pazopanib PK and to estimate the pazopanib clearance of a patient regardless of the time of sampling. Data from the therapeutic drug monitoring (TDM) of patients with cancer at Institute Gustave Roussy and a clinical study (phase I/II) that evaluates the tolerance to pazopanib were used. From the individual clearance, it is then possible to obtain the patient’s AUC. A target AUC for maximum efficacy and minimum side effects of 750 mg·h·L−1 was determined. The comparison of the estimated AUC with the target AUC would enable us to determine whether plasma exposure is adequate or whether it would be necessary to propose therapeutic adjustments.

scholarly journals Population Pharmacokinetics and Dosing Optimization of Ceftazidime in Infants

2018 ◽  
Vol 62 (4) ◽  
Author(s):  
Zhong-Ren Shi ◽  
Xing-Kai Chen ◽  
Li-Yuan Tian ◽  
Ya-Kun Wang ◽  
Gu-Ying Zhang ◽  
...  
Keyword(s):  
Population Pharmacokinetics ◽  
High Performance ◽  
Compartment Model ◽  
Population Pharmacokinetic Analysis ◽  
Generation Cephalosporin ◽  
Pharmacokinetic Analysis ◽  
Population Pharmacokinetic ◽  
Pharmacokinetic Data ◽  
Dosing Regimen ◽  
Age Range

ABSTRACT Ceftazidime, a third-generation cephalosporin, can be used for the treatment of adults and children with infections due to susceptible bacteria. To date, the pediatric pharmacokinetic data are limited in infants, and therefore we aimed to evaluate the population pharmacokinetics of ceftazidime in infants and to define the appropriate dose to optimize ceftazidime treatment. Blood samples were collected from children treated with ceftazidime, and concentrations of the drug were quantified by high-performance liquid chromatography with UV detection (HPLC-UV). A population pharmacokinetic analysis was performed using NONMEM software ( version 7.2.0). Fifty-one infants ( age range, 0.1 to 2.0 years ) were included. Sparse pharmacokinetic samples ( n = 90 ) were available for analysis. A one-compartment model with first-order elimination showed the best fit with the data. A covariate analysis identified that body weight and creatinine clearance (CL CR ) were significant covariates influencing ceftazidime clearance. Monte Carlo simulation demonstrated that the currently used dosing regimen of 50 mg / kg twice daily was associated with a high risk of underdosing in infants. In order to reach the target of 70% of the time that the free antimicrobial drug concentration exceeds the MIC ( fT >MIC ), 25 mg/kg every 8 h (q8h) and 50 mg/kg q8h were required for MICs of 4 and 8 mg/liter, respectively. The population pharmacokinetic characteristics of ceftazidime were evaluated in infants. An evidence-based dosing regimen was established based on simulation.

scholarly journals Telavancin Penetration into Human Epithelial Lining Fluid Determined by Population Pharmacokinetic Modeling and Monte Carlo Simulation

2008 ◽  
Vol 52 (7) ◽  
pp. 2300-2304 ◽  
Author(s):  
Thomas P. Lodise ◽  
Mark Gotfried ◽  
Steven Barriere ◽  
George L. Drusano
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Pharmacokinetic Analysis ◽  
Population Pharmacokinetic ◽  
Model Parameters ◽  
Pharmacokinetic Data ◽  
Epithelial Lining ◽  
Time Curve ◽  
Epithelial Lining Fluid ◽  
Concentration Time

ABSTRACT Telavancin is an investigational bactericidal lipoglycopeptide with a multifunctional mechanism of action, as demonstrated against methicillin-resistant Staphylococcus aureus. While the plasma pharmacokinetics have been described, the extent of the penetration of the drug into the lung, measured by the epithelial lining fluid (ELF), remains unknown. Population modeling and Monte Carlo simulation were employed to estimate the penetration of telavancin into ELF. Plasma and ELF pharmacokinetic data were obtained from 20 healthy volunteers, and the pharmacokinetic samples were assayed by a validated liquid chromatography-tandem mass spectrometry technique. Concentration-time profiles in plasma and ELF were simultaneously modeled using a three-compartment model with zero-order infusion and first-order elimination and transfer. The model parameters were identified in a population pharmacokinetic analysis (BigNPAG). Monte Carlo simulation of 9,999 subjects was performed to calculate the ELF/plasma penetration ratios by estimating the area under the concentration-time curve (AUC) for the drug in ELF (AUCELF) and for the free drug in plasma (free AUCplasma) from zero to infinity after a single dose. After the Bayesian step, the overall fits of the model to the data were good, and plots of predicted versus observed concentrations in plasma and ELF showed slopes and intercepts very close to the ideal values of 1.0 and 0.0, respectively. The median AUCELF/free AUCplasma penetration ratio was 0.73, and the 25th and 75th percentile value ratios were 0.43 and 1.24, respectively. In uninfected lung tissue, the median AUCELF is approximately 75% of the free AUCplasma.

scholarly journals Population Pharmacokinetic Analysis of Isoniazid among Pulmonary Tuberculosis Patients from China

2020 ◽  
Vol 64 (3) ◽  
Author(s):  
Wei Jing ◽  
Zhaojing Zong ◽  
Bohao Tang ◽  
Jing Wang ◽  
Tingting Zhang ◽  
...  
Keyword(s):  
Compartment Model ◽  
Population Pharmacokinetic Analysis ◽  
Slow Acetylators ◽  
Pharmacokinetic Analysis ◽  
Population Pharmacokinetic ◽  
Time Curve ◽  
Tuberculosis Patients ◽  
Two Compartment Model ◽  
Acetylator Status ◽  
Liquid Chromatography Tandem Mass

ABSTRACT The blood concentration of isoniazid (INH) is evidently affected by polymorphisms in N-acetyltransferase 2 (NAT2), an enzyme that is primarily responsible for the trimodal (i.e., fast, intermediate, and slow) INH elimination. The pharmacokinetic (PK) variability, driven largely by NAT2 activity, creates a challenge for the deployment of a uniform INH dosage in tuberculosis (TB) patients. Although acetylator-specific INH dosing has long been suggested, well-recognized dosages according to acetylator status remain elusive. In this study, 175 blood samples were collected from 89 pulmonary TB patients within 0.5 to 6 h after morning INH administration. According to their NAT2 genotypes, 32 (36.0%), 38 (42.7%), and 19 (21.3%) were fast, intermediate, and slow acetylators, respectively. The plasma INH concentration was detected by liquid chromatography-tandem mass spectrometry. Population pharmacokinetic (PPK) analysis was conducted using NONMEM and R software. A two-compartment model with first-order absorption and elimination well described the PK parameters of isoniazid. Body weight and acetylator status significantly affected the INH clearance rate. The dosage simulation targeting three indicators, including the well-recognized efficacy-safety indicator maximum concentration in serum (Cmax; 3 to 6 μg/ml), the reported area under the concentration-time curve from 0 h to infinity (AUC0–∞; ≥10.52 μg·h/ml), and the 2-h INH serum concentrations (≥2.19 μg/ml), was associated with the strongest early bactericidal activity. The optimal dosages targeting the different indicators varied from 700 to 900 mg/day, 500 to 600 mg/day, and 300 mg/day for the rapid, intermediate, and slow acetylators, respectively. Furthermore, a PPK model for isoniazid among Chinese tuberculosis patients was established for the first time and suggested doses of approximately 800 mg/day, 500 mg/day, and 300 mg/day for fast, intermediate, and slow acetylators, respectively, after a trade-off between efficacy and the occurrence of side effects.

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