Cytotoxicity of Dimethylacetamide and Pharmacokinetics in Children Receiving Intravenous Busulfan

2007 ◽  
Vol 25 (13) ◽  
pp. 1772-1778 ◽  
Author(s):  
Georg Hempel ◽  
Doris Oechtering ◽  
Claudia Lanvers-Kaminsky ◽  
Thomas Klingebiel ◽  
Josef Vormoor ◽  
...  
Keyword(s):  
Safety Concern ◽  
Plasma Concentrations ◽  
Leukemic Cell ◽  
Population Pharmacokinetic Analysis ◽  
Volume Of Distribution ◽  
Pharmacokinetic Analysis ◽  
Population Pharmacokinetic ◽  
High Dose ◽  
Leukemic Cell Lines

PurposeTo assess the cytotoxicity and the exposure of N,N-dimethylacetamide (DMA) in children during high-dose therapy with an intravenous (IV) formulation of busulfan containing the potentially hepatotoxic and neurotoxic DMA as a solvent.Patients and MethodsEighteen children aged 0.9 to 17.3 years (median age, 4.0 years) received IV busulfan in 15 doses of 0.7 to 1.0 mg/kg busulfan containing overall DMA amounts of between 5 mmol (437 mg) and 70.5 mmol (6,142 mg) per dose. Plasma concentrations of DMA and busulfan were quantified and analyzed using nonlinear mixed-effects modeling. Four different leukemic cell lines were incubated with DMA, and cytotoxicity was assessed in comparison with busulfan as well as in a combination reflecting the ratio in the formulation.ResultsMaximal plasma concentrations of DMA up to 3.09 mmol/L were observed. No accumulation of the solvent occurred. Instead, the trough levels decreased over the 4 treatment days. The population pharmacokinetic analysis revealed a clearance of 86.9 mL h−1kg−1± 27% that increased to 298 mL h−1kg−1on the fourth day and a volume of distribution of 469 mL kg ± 22% (population mean ± interindividual variability). DMA volume of distribution correlated with the volume of distribution of busulfan. The cytotoxicity of DMA in vitro was 3 orders of magnitude lower than that of busulfan. No synergism was observed.ConclusionThe lack of accumulation of DMA confirms that there is no safety concern related to the DMA content in this IV busulfan formulation. The contribution of DMA to the antileukemic effect of the formulation seems to be limited.

Population Pharmacokinetic and Concentration-QTc Analysis of Delamanid in Pediatric Participants with Multidrug-Resistant Tuberculosis

2021 ◽  
Author(s):  
Tomohiro Sasaki ◽  
Elin M. Svensson ◽  
Xiaofeng Wang ◽  
Yanlin Wang ◽  
Jeffrey Hafkin ◽  
...  
Keyword(s):  
Plasma Concentrations ◽  
Population Pharmacokinetic Analysis ◽  
Apparent Volume ◽  
Multidrug Resistant ◽  
Volume Of Distribution ◽  
Pharmacokinetic Analysis ◽  
Population Pharmacokinetic ◽  
Resistant Tuberculosis ◽  
Multidrug Resistant Tuberculosis ◽  
Mdr Tb

A population pharmacokinetic analysis of delamanid and its major metabolite DM-6705 was conducted to characterize the pharmacokinetics of delamanid and DM-6705 in pediatric participants with multidrug-resistant tuberculosis (MDR-TB). Data from participants between the ages of 0.67 to 17 years old, enrolled in 2 clinical trials, were utilized for the analysis. The final dataset contained 634 delamanid and 706 DM-6705 valid plasma concentrations from 37 children. A transit model with three compartments best described the absorption of delamanid. Two compartment models for each component with linear elimination were selected to characterize the disposition of delamanid and DM-6705, respectively. The covariates included in the model were body weight on apparent volume of distribution and apparent clearance (for both delamanid and DM-6705); formulation (dispersible vs film coated tablet) on mean absorption time; age, formulation, and dose on bioavailability of delamanid; age on the fraction of delamanid metabolized to DM-6705. Based on the simulations, doses for participants within different age/weight groups that result in delamanid exposure comparable to that in adults following the approved adult dose were calculated. By concentration-QTc (QTcB, QT corrected by Bazett’s' formula) analysis, a significant positive correlation was detected with concentrations of DM-6705. However, the model-predicted upper bounds of the 90% confidence intervals of ΔQTc value were less than 10 ms at the simulated Cmax of DM-6705 following administration of maximum doses simulated. This suggests that the effect on the QT interval following the proposed dosing is unlikely to be clinically meaningful in children with MDR-TB who receive delamanid.

scholarly journals A Population Pharmacokinetic Analysis Shows that Arylacetamide Deacetylase (AADAC) Gene Polymorphism and HIV Infection Affect the Exposure of Rifapentine

2019 ◽  
Vol 63 (4) ◽  
Author(s):  
Jose Francis ◽  
Simbarashe P. Zvada ◽  
Paolo Denti ◽  
Mark Hatherill ◽  
Salome Charalambous ◽  
...  
Keyword(s):  
Food Intake ◽  
Hiv Infection ◽  
Pregnane X Receptor ◽  
Compartment Model ◽  
Population Pharmacokinetic Analysis ◽  
Volume Of Distribution ◽  
Fat Free Mass ◽  
Pharmacokinetic Analysis ◽  
Population Pharmacokinetic ◽  
Antituberculosis Treatment

ABSTRACT Rifapentine is a rifamycin used to treat tuberculosis. As is the case for rifampin, plasma exposures of rifapentine are associated with the treatment response. While concomitant food intake and HIV infection explain part of the pharmacokinetic variability associated with rifapentine, few studies have evaluated the contribution of genetic polymorphisms. We evaluated the effects of functionally significant polymorphisms of the genes encoding OATP1B1, the pregnane X receptor (PXR), constitutive androstane (CAR), and arylacetamide deacetylase (AADAC) on rifapentine exposure. Two studies evaluating novel regimens among southern African patients with drug-susceptible pulmonary tuberculosis were included in this analysis. In the RIFAQUIN study, rifapentine was administered in the continuation phase of antituberculosis treatment in 1,200-mg-once-weekly or 900-mg-twice-weekly doses. In the Daily RPE study, 450 or 600 mg was given daily during the intensive phase of treatment. Nonlinear mixed-effects modeling was used to describe the pharmacokinetics of rifapentine and to identify significant covariates. A total of 1,144 drug concentration measurements from 326 patients were included in the analysis. Pharmacogenetic information was available for 162 patients. A one-compartment model with first-order elimination and transit compartment absorption described the data well. In a typical patient (body weight, 56 kg; fat-free mass, 45 kg), the values of clearance and volume of distribution were 1.33 liters/h and 25 liters, respectively. Patients carrying the AA variant (65.4%) of AADAC rs1803155 were found to have a 10.4% lower clearance. HIV-infected patients had a 21.9% lower bioavailability. Once-weekly doses of 1,200 mg were associated with a reduced clearance (13.2%) compared to that achieved with more frequently administered doses. Bioavailability was 23.3% lower among patients participating in the Daily RPE study than in those participating in the RIFAQUIN study. This is the first study to report the effect of AADAC rs1803155AA on rifapentine clearance. The observed increase in exposure is modest and unlikely to be of clinical relevance. The difference in bioavailability between the two studies is probably related to the differences in food intake concomitant with the dose. HIV-coinfected patients had lower rifapentine exposures.

scholarly journals The influence of CYP2C8*3 on carbamazepine serum concentration in epileptic pediatric patients

2016 ◽  
Vol 19 (1) ◽  
pp. 21-28 ◽  
Author(s):  
DD Milovanovic ◽  
JR Milovanovic ◽  
M Radovanovic ◽  
I Radosavljevic ◽  
S Obradovic ◽  
...  
Keyword(s):  
Serum Concentration ◽  
High Performance ◽  
Dose Adjustment ◽  
Pediatric Patients ◽  
Plasma Concentrations ◽  
Clinical Importance ◽  
Population Pharmacokinetic Analysis ◽  
Pharmacokinetic Analysis ◽  
Population Pharmacokinetic ◽  
Allele Specific

AbstractThe aim of the present study was to investigate the distribution of CYP2C8 variants *3 and *5, as well as their effect on carbamazepine pharmacokinetic properties, in 40 epileptic pediatric patients on carbamazepine treatment. Genotyping was conducted using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), and allele-specific (AS)-PCR methods, and steady-state carbamazepine plasma concentrations were determined by high performance liquid chromatography (HPLC). The CYP2C8 *3 and *5 polymorphisms were found at frequencies of 17.5 and 0.0%, respectively. After dose adjustment, there was a difference in daily dose in CYP2C8*3 carriers compared to non carriers [mean ± standard deviation (SD): 14.19 ± 5.39 vs. 15.46 ± 4.35 mg/kg; p = 0.5]. Dose-normalized serum concentration of carbamazepine was higher in CYP2C8*3 (mean ± SD: 0.54 ± 0.18 vs. 0.43 ± 0.11 mg/mL, p = 0.04), and the observed correlation between weight-adjusted carbamazepine dose and carbamazepine concentration after dose adjustment was significant only in CYP2C8*3 non carriers (r = 0.52, p = 0.002). However, the population pharmacokinetic analysis failed to demonstrate any significant effect of CYP2C8 *3 polymorphism on carbamazepine clearance [CL L/h = 0.215 + 0.0696*SEX+ 0.000183*DD]. The results indicated that the CYP2C8*3 polymorphism might not be of clinical importance for epilepsy treatment in pediatric populations.

scholarly journals Interventional cohort study of prolonged use (>72 hours) of paracetamol in neonates: protocol of the PARASHUTE study

2019 ◽  
Vol 3 (1) ◽  
pp. e000427 ◽  
Author(s):  
Sissel Sundell Haslund-Krog ◽  
Steen Hertel ◽  
Kim Dalhoff ◽  
Susanne Poulsen ◽  
Ulla Christensen ◽  
...  
Keyword(s):  
Cohort Study ◽  
Neonatal Intensive Care ◽  
Plasma Concentrations ◽  
Population Pharmacokinetic Analysis ◽  
Pharmacokinetic Analysis ◽  
Population Pharmacokinetic ◽  
Concomitant Treatment ◽  
Pain Scores ◽  
Postmenstrual Age ◽  
Dosing Strategies

IntroductionAnticipated or actual pain in neonates results in use of paracetamol for prolonged pain relief in many neonatal intensive care units. Clinical trials examining safety of paracetamol exposure in neonates have been of short duration (1–3 days) and hepatic biomarkers and paracetamol metabolism are rarely reported in the same studies.We aim to investigate the safety (hepatic tolerance) and effectiveness of prolonged paracetamol exposure in neonates by measuring hepatic biomarkers, plasma concentrations of paracetamol and its metabolites and pain scores. In addition, we study a possible interaction between ethanol and paracetamol.Methods and analysisA multicentre interventional cohort study.Neonates of any gestational age and up to 44 weeks postmenstrual age, treated with oral or intravenous paracetamol can be included.Alanine aminotransferase (ALT) and bilirubin are measured at baseline or within 24 hours after treatment initiation. P-paracetamol and metabolites are measured at steady state and every 2 days (opportunistically) together with ALT and bilirubin and lastly after discontinuation of treatment. COMFORT neo pain scores are collected longitudinally. COMFORT neo pain scores and population pharmacokinetic analysis of paracetamol samples will be analysed simultaneously using non-linear mixed effects models. One and two compartment models with first-order elimination will be tested for disposition. In addition, plasma ethanol is measured if the patient receives concomitant treatment with intravenous or oral phenobarbital containing ethanol as an excipient.Ethics and disseminationInclusion of patients can be postponed 24 hours after the first paracetamol dose. This is intended to make the inclusion process less stressful for parents. This study uses standard dosing strategies. The potential risks are additional blood samples, which are collected opportunistically to reduce additional heel pricks.Trial registrationnumberEthics Comittee: H-17027244, EudraCT no: 2017-002724-25, BFH-2017–106, 05952.

scholarly journals Pharmacokinetic Properties of Single-Dose Primaquine in Papua New Guinean Children: Feasibility of Abbreviated High-Dose Regimens for Radical Cure of Vivax Malaria

2013 ◽  
Vol 58 (1) ◽  
pp. 432-439 ◽  
Author(s):  
Brioni R. Moore ◽  
Sam Salman ◽  
John Benjamin ◽  
Madhu Page-Sharp ◽  
Leanne J. Robinson ◽  
...  
Keyword(s):  
Single Dose ◽  
Vivax Malaria ◽  
Venous Blood ◽  
Plasma Concentrations ◽  
Volume Of Distribution ◽  
Population Pharmacokinetic ◽  
High Dose ◽  
Pharmacokinetic Data ◽  
Radical Cure ◽  
Papua New Guinean

ABSTRACTSince conventional 14-day primaquine (PMQ) radical cure of vivax malaria is associated with poor compliance, and as total dose, not therapy duration, determines efficacy, a preliminary pharmacokinetic study of two doses (0.5 and 1.0 mg/kg of body weight) was conducted in 28 healthy glucose-6-phosphate dehydrogenase-normal Papua New Guinean children, aged 5 to 12 years, to facilitate development of abbreviated high-dose regimens. Dosing was with food and was directly observed, and venous blood samples were drawn during a 168-h postdose period. Detailed safety monitoring was performed for hepatorenal function and hemoglobin and methemoglobin concentrations. Plasma concentrations of PMQ and its metabolite carboxyprimaquine (CPMQ) were determined by liquid chromatography-mass spectrometry and analyzed using population pharmacokinetic methods. The derived models were used in simulations. Both single-dose regimens were well tolerated with no changes in safety parameters. The mean PMQ central volume of distribution and clearance relative to bioavailability (200 liters/70 kg and 24.6 liters/h/70 kg) were within published ranges for adults. The median predicted maximal concentrations (Cmax) for both PMQ and CPMQ after the last dose of a 1.0 mg/kg 7-day PMQ regimen were approximately double those at the end of 14 days of 0.5 mg/kg daily, while a regimen of 1.0 mg/kg twice daily resulted in a 2.38 and 3.33 times higherCmaxfor PMQ and CPMQ, respectively. All predicted medianCmaxconcentrations were within ranges for adult high-dose studies that also showed acceptable safety and tolerability. The present pharmacokinetic data, the first for PMQ in children, show that further studies of abbreviated high-dose regimens are feasible in this age group.

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 Safety and Population Pharmacokinetic Analysis of Intravenous Acetaminophen in Neonates, Infants, Children, and Adolescents With Pain or Fever

2011 ◽  
Vol 16 (4) ◽  
pp. 246-261 ◽  
Author(s):  
Athena F. Zuppa ◽  
Gregory B. Hammer ◽  
Jeffrey S. Barrett ◽  
Brian F. Kenney ◽  
Nastya Kassir ◽  
...  
Keyword(s):  
Children And Adolescents ◽  
Phase 1 ◽  
Plasma Concentrations ◽  
Age Groups ◽  
Rectal Administration ◽  
Population Pharmacokinetic Analysis ◽  
Pharmacokinetic Analysis ◽  
Pharmacokinetic Parameters ◽  
Population Pharmacokinetic ◽  
Intravenous Acetaminophen

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 <2 years), children (2 to <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.

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