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 ◽  
...  

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.

2019 ◽  
Vol 37 (4_suppl) ◽  
pp. 86-86
Author(s):  
Takuro Mizukami ◽  
Masashi Takeuchi ◽  
Chiyo K. Imamura ◽  
Eisuke Booka ◽  
HIROYA TAKEUCHI ◽  
...  

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.


2016 ◽  
Vol 60 (8) ◽  
pp. 4568-4576 ◽  
Author(s):  
Laura L. Kovanda ◽  
Amit V. Desai ◽  
Qiaoyang Lu ◽  
Robert W. Townsend ◽  
Shahzad Akhtar ◽  
...  

ABSTRACTIsavuconazonium sulfate (Cresemba; Astellas Pharma Inc.), a water-soluble prodrug of the triazole antifungal agent isavuconazole, is available for the treatment of invasive aspergillosis (IA) and invasive mucormycosis. A population pharmacokinetic (PPK) model was constructed using nonparametric estimation to compare the pharmacokinetic (PK) behaviors of isavuconazole in patients treated in the phase 3 VITAL open-label clinical trial, which evaluated the efficacy and safety of the drug for treatment of renally impaired IA patients and patients with invasive fungal disease (IFD) caused by emerging molds, yeasts, and dimorphic fungi. Covariates examined were body mass index (BMI), weight, race, impact of estimated glomerular filtration rate (eGFR) on clearance (CL), and impact of weight on volume. PK parameters were compared based on IFD type and other patient characteristics. Simulations were performed to describe the MICs covered by the clinical dosing regimen. Concentrations (n= 458) from 136 patients were used to construct a 2-compartment model (first-order absorption compartment and central compartment). Weight-related covariates affected clearance, but eGFR did not. PK parameters and intersubject variability of CL were similar across different IFD groups and populations. Target attainment analyses demonstrated that the clinical dosing regimen would be sufficient for total drug area under the concentration-time curve (AUC)/MIC targets ranging from 50.5 forAspergillusspp. (up to the CLSI MIC of 0.5 mg/liter) to 270 and 5,053 forCandida albicans(up to MICs of 0.125 and 0.004 mg/liter, respectively) and 312 for non-albicans Candidaspp. (up to a MIC of 0.125 mg/liter). The estimations forCandidaspp. were exploratory considering that no patients withCandidainfections were included in the current analyses. (The VITAL trial is registered at ClinicalTrials.gov under number NCT00634049.)


1996 ◽  
Vol 40 (6) ◽  
pp. 1360-1365 ◽  
Author(s):  
J M Jacobson ◽  
M Davidian ◽  
P M Rainey ◽  
R Hafner ◽  
R H Raasch ◽  
...  

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.


2019 ◽  
Vol 63 (4) ◽  
Author(s):  
Brady S. Moffett ◽  
Vijay Ivaturi ◽  
Jennifer Morris ◽  
Ayse Akcan Arikan ◽  
Ankhi Dutta

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.


2013 ◽  
Vol 57 (5) ◽  
pp. 2141-2146 ◽  
Author(s):  
Jongtae Lee ◽  
Seunghoon Han ◽  
Sangil Jeon ◽  
Taegon Hong ◽  
Wonkeun Song ◽  
...  

ABSTRACTColistin is increasingly used as a salvage therapy for nosocomial infections caused by multidrug-resistant Gram-negative bacteria such asPseudomonas aeruginosaandAcinetobacter baumannii. However, the available pharmacokinetic (PK) data for colistin are limited to guide dosing. The aim of this study was to develop a population PK model of colistin and to identify the optimal dosage regimens for burn patients. Fifty patients with burns ranging from 4% to 85% of total body surface area who had been treated with colistimethate sodium (CMS) were studied. CMS, which is hydrolyzedin vivoto an active metabolite, was intravenously administered every 12 h. Blood samples were collected at 0, 1, 2, 4, 6, and 8 h after more than five infusions to measure the colistin concentration using a liquid chromatography-tandem mass spectrometry (LC-MS/MS) system. The population PK model was developed using nonlinear mixed effect modeling (NONMEM, v. 6.2). A one-compartment linear PK model for colistin best described the data. The covariates included in the final model were creatinine clearance for the relative fraction of CMS converted into colistin and the presence of edema for the turnover rate constant of CMS converted into colistin. A steady-state 24-h area under the concentration-time curve was simulated from 1,000 virtual patients receiving 150 mg colistin base activity every 12 h using the final model. Relative to previous studies with critically ill patients, the elimination half-life of colistin (6.6 h) was much shorter, and continuous renal replacement therapy was not a significant covariate for any PK parameters.


2012 ◽  
Vol 56 (6) ◽  
pp. 3032-3042 ◽  
Author(s):  
Lena E. Friberg ◽  
Patanjali Ravva ◽  
Mats O. Karlsson ◽  
Ping Liu

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.


2019 ◽  
Vol 24 (2) ◽  
pp. 107-116 ◽  
Author(s):  
Brady S. Moffett ◽  
Karla Resendiz ◽  
Jennifer Morris ◽  
Ayse Akcan-Arikan ◽  
Paul A. Checchia

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.


2018 ◽  
Vol 62 (4) ◽  
Author(s):  
Zhong-Ren Shi ◽  
Xing-Kai Chen ◽  
Li-Yuan Tian ◽  
Ya-Kun Wang ◽  
Gu-Ying Zhang ◽  
...  

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.


2015 ◽  
Vol 59 (11) ◽  
pp. 6791-6799 ◽  
Author(s):  
Kok-Yong Seng ◽  
Kim-Hor Hee ◽  
Gaik-Hong Soon ◽  
Nicholas Chew ◽  
Saye H. Khoo ◽  
...  

ABSTRACTIn this study, we aimed to quantify the effects of theN-acetyltransferase 2 (NAT2) phenotype on isoniazid (INH) metabolismin vivoand identify other sources of pharmacokinetic variability following single-dose administration in healthy Asian adults. The concentrations of INH and its metabolites acetylisoniazid (AcINH) and isonicotinic acid (INA) in plasma were evaluated in 33 healthy Asians who were also given efavirenz and rifampin. The pharmacokinetics of INH, AcINH, and INA were analyzed using nonlinear mixed-effects modeling (NONMEM) to estimate the population pharmacokinetic parameters and evaluate the relationships between the parameters and the elimination status (fast, intermediate, and slow acetylators), demographic status, and measures of renal and hepatic function. A two-compartment model with first-order absorption best described the INH pharmacokinetics. AcINH and INA data were best described by a two- and a one-compartment model, respectively, linked to the INH model. In the final model for INH, the derived metabolic phenotypes for NAT2 were identified as a significant covariate in the INH clearance, reducing its interindividual variability from 86% to 14%. The INH clearance in fast eliminators was 1.9- and 7.7-fold higher than in intermediate and slow eliminators, respectively (65 versus 35 and 8 liters/h). Creatinine clearance was confirmed as a significant covariate for AcINH clearance. Simulations suggested that the current dosing guidelines (200 mg for 30 to 45 kg and 300 mg for >45 kg) may be suboptimal (3 mg/liter ≤Cmax≤ 6 mg/liter) irrespective of the acetylator class. The analysis established a model that adequately characterizes INH, AcINH, and INA pharmacokinetics in healthy Asians. Our results refine the NAT2 phenotype-based predictions of the pharmacokinetics for INH.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ko Nonoshita ◽  
Yosuke Suzuki ◽  
Ryota Tanaka ◽  
Tetsuya Kaneko ◽  
Yoshifumi Ohchi ◽  
...  

AbstractWe aimed to construct a novel population pharmacokinetics (PPK) model of doripenem (DRPM) for Japanese patients in intensive care unit, incorporating the clearance of DRPM by continuous renal replacement therapy (CRRT). Twenty-one patients treated with DRPM (0.25 or 0.5 g) by intravenous infusion over 1 h were included in the study. Nine of the 21 patients were receiving CRRT. Plasma samples were obtained before and 1, 2, 4, 6 and 8 h after the first DRPM administration. PPK analysis was conducted by nonlinear mixed effects modeling using a two-compartment model. Total clearance (CLtotal) in the model was divided into CRRT clearance (CLCRRT) and body clearance (CLbody). The final model was: CLtotal (L h−1) = CLbody(non-CRRT) = 3.65 × (Ccr/62.25)0.64 in the absence of CRRT, or = CLbody(CRRT) + CLCRRT = 2.49 × (Ccr/52.75)0.42 + CLCRRT in the presence of CRRT; CLCRRT = QE × 0.919 (0.919 represents non-protein binding rate of DRPM); V1 (L) = 10.04; V2 (L) = 8.13; and Q (L h−1) = 3.53. Using this model, CLtotal was lower and the distribution volumes (V1 and V2) tended to be higher compared to previous reports. Also, Ccr was selected as a significant covariate for CLbody. Furthermore, the contribution rate of CLCRRT to CLtotal was 30–40%, suggesting the importance of drug removal by CRRT. The population analysis model used in this study is a useful tool for planning DRPM regimen and administration. Our novel model may contribute greatly to proper use of DRPM in patients requiring intensive care.


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