Predictive ability of published population pharmacokinetic models of valproic acid in Thai manic patients

2020 ◽  
Vol 46 (1) ◽  
pp. 198-207
Author(s):  
Janthima Methaneethorn ◽  
Nattawut Leelakanok
Keyword(s):  
Valproic Acid ◽  
Predictive Ability ◽  
Population Pharmacokinetic ◽  
Pharmacokinetic Models ◽  
Manic Patients

scholarly journals External Evaluation of Population Pharmacokinetic Models and Bayes-Based Dosing of Infliximab

Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1191
Author(s):  
Celine Konecki ◽  
Catherine Feliu ◽  
Yoann Cazaubon ◽  
Delphine Giusti ◽  
Marcelle Tonye-Libyh ◽  
...  
Keyword(s):  
Goodness Of Fit ◽  
Inflammatory Diseases ◽  
Plasma Concentrations ◽  
Population Pharmacokinetic ◽  
Pharmacokinetic Models ◽  
External Evaluation ◽  
Immunomodulatory Treatment ◽  
Weighted Residuals ◽  
Prediction Distribution ◽  
Target Plasma

Despite the well-demonstrated efficacy of infliximab in inflammatory diseases, treatment failure remains frequent. Dose adjustment using Bayesian methods has shown in silico its interest in achieving target plasma concentrations. However, most of the published models have not been fully validated in accordance with the recommendations. This study aimed to submit these models to an external evaluation and verify their predictive capabilities. Eight models were selected for external evaluation, carried out on an independent database (409 concentrations from 157 patients). Each model was evaluated based on the following parameters: goodness-of-fit (comparison of predictions to observations), residual error model (population weighted residuals (PWRES), individual weighted residuals (IWRES), and normalized prediction distribution errors (NPDE)), and predictive performances (prediction-corrected visual predictive checks (pcVPC) and Bayesian simulations). The performances observed during this external evaluation varied greatly from one model to another. The eight evaluated models showed a significant bias in population predictions (from −7.19 to 7.38 mg/L). Individual predictions showed acceptable bias and precision for six of the eight models (mean error of −0.74 to −0.29 mg/L and mean percent error of −16.6 to −0.4%). Analysis of NPDE and pcVPC confirmed these results and revealed a problem with the inclusion of several covariates (weight, concomitant immunomodulatory treatment, presence of anti-drug antibodies). This external evaluation showed satisfactory results for some models, notably models A and B, and highlighted several prospects for improving the pharmacokinetic models of infliximab for clinical-biological application.

External evaluation of published population pharmacokinetic models of polymyxin B

2021 ◽  
Author(s):  
Ya-qian Li ◽  
Kai-feng Chen ◽  
Jun-jie Ding ◽  
Hong-yi Tan ◽  
Nan Yang ◽  
...  
Keyword(s):  
Polymyxin B ◽  
Population Pharmacokinetic ◽  
Pharmacokinetic Models ◽  
External Evaluation

scholarly journals Pharmacokinetics-Pharmacodynamics of Gatifloxacin in a Lethal Murine Bacillus anthracis Inhalation Infection Model

2007 ◽  
Vol 51 (12) ◽  
pp. 4351-4355 ◽  
Author(s):  
Paul G. Ambrose ◽  
Alan Forrest ◽  
William A. Craig ◽  
Chistopher M. Rubino ◽  
Sujata M. Bhavnani ◽  
...  
Keyword(s):  
Bacillus Anthracis ◽  
Survival Data ◽  
Sensitivity Analyses ◽  
Maximum Effect ◽  
Infection Model ◽  
Population Pharmacokinetic ◽  
Pharmacokinetic Models ◽  
Concentration Time ◽  
Dosing Regimens ◽  
Adults And Children

ABSTRACT We determined the pharmacokinetic-pharmacodynamic (PK-PD) measure most predictive of gatifloxacin efficacy and the magnitude of this measure necessary for survival in a murine Bacillus anthracis inhalation infection model. We then used population pharmacokinetic models for gatifloxacin and simulation to identify dosing regimens with high probabilities of attaining exposures likely to be efficacious in adults and children. In this work, 6- to 8-week-old nonneutropenic female BALB/c mice received aerosol challenges of 50 to 75 50% lethal doses of B. anthracis (Ames strain, for which the gatifloxacin MIC is 0.125 mg/liter). Gatifloxacin was administered at 6- or 8-h intervals beginning 24 h postchallenge for 21 days, and dosing was designed to produce profiles mimicking fractionated concentration-time profiles for humans. Mice were evaluated daily for survival. Hill-type models were fitted to survival data. To identify potentially effective dosing regimens, adult and pediatric population pharmacokinetic models for gatifloxacin and Monte Carlo simulation were used to generate 5,000 individual patient exposure estimates. The ratio of the area under the concentration-time curve from 0 to 24 h (AUC0-24) to the MIC of the drug for the organism (AUC0-24/MIC ratio) was the PK-PD measure most predictive of survival (R 2 = 0.96). The 50% effective dose (ED50) and the ED90 and ED99 corresponded to AUC0-24/MIC ratios of 11.5, 15.8, and 30, respectively, where the maximum effect was 97% survival. Simulation results indicate that a daily gatifloxacin dose of 400 mg for adults and 10 mg/kg of body weight for children gives a 100% probability of attaining the PK-PD target (ED99). Sensitivity analyses suggest that the probability of PK-PD target attainment in adults and children is not affected by increases in MICs for strains of B. anthracis to levels as high as 0.5 mg/liter.

scholarly journals External validation of the predictive performance of population pharmacokinetic models for phenobarbital in pediatric patients

2020 ◽  
Author(s):  
Sunae Ryu ◽  
Woo Jin Jung ◽  
Zheng Jiao ◽  
Jung Woo Chae ◽  
Hwi-yeol Yun
Keyword(s):  
External Validation ◽  
Predictive Performance ◽  
Validation Dataset ◽  
Therapeutic Drug ◽  
Population Pharmacokinetic ◽  
Pharmacokinetic Models ◽  
Bayesian Forecasting ◽  
Predictive Capability ◽  
Young Infants ◽  
Simulation Based

Aim: Several studies have reported population pharmacokinetic models for phenobarbital (PB), but the predictive performance of these models has not been well documented. This study aims to do external validation of the predictive performance in published pharmacokinetic models. Methods: Therapeutic drug monitoring data collected in neonates and young infants treated with PB for seizure control, was used for external validation. A literature review was conducted through PubMed to identify population pharmacokinetic models. Prediction- and simulation-based diagnostics, and Bayesian forecasting were performed for external validation. The incorporation of size or maturity functions into the published models was also tested for prediction improvement. Results: A total of 79 serum concentrations from 28 subjects were included in the external validation dataset. Seven population pharmacokinetic studies of PB were selected for evaluation. The model by Voller et al. [27] showed the best performance concerning prediction-based evaluation. In simulation-based analyses, the normalized prediction distribution error of two models (those of Shellhaas et al. [24] and Marsot et al. [25]) obeyed a normal distribution. Bayesian forecasting with more than one observation improved predictive capability. Incorporation of both allometric size scaling and maturation function generally enhanced the predictive performance, but with marked improvement for the adult pharmacokinetic model. Conclusion: The predictive performance of published pharmacokinetic models of PB was diverse, and validation may be necessary to extrapolate to different clinical settings. Our findings suggest that Bayesian forecasting improves the predictive capability of individual concentrations for pediatrics.

Tacrolimus population pharmacokinetic models according to CYP3A5/CYP3A4/POR genotypes in Chinese Han renal transplant patients

2018 ◽  
Vol 19 (13) ◽  
pp. 1013-1025 ◽  
Author(s):  
Wan Zhu ◽  
Ling Xue ◽  
Hongwei Peng ◽  
Zhouping Duan ◽  
Xuelian Zheng ◽  
...  
Keyword(s):  
Renal Transplant ◽  
Population Pharmacokinetic ◽  
Pharmacokinetic Models ◽  
Chinese Han ◽  
Transplant Patients ◽  
Renal Transplant Patients
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