Population Pharmacokinetic Analysis of Didanosine (2′,3′-Dideoxyinosine) Plasma Concentrations Obtained in Phase I Clinical Trials in Patients with AIDS or AIDS-Related Complex

1992 ◽  
Vol 32 (3) ◽  
pp. 242-247 ◽  
Author(s):  
Sudhakar M. Pai ◽  
Umesh A. Shukla ◽  
Thaddeus H. Grasela ◽  
Catherine A. Knupp ◽  
Raphael Dolin ◽  
...  
2016 ◽  
Vol 19 (1) ◽  
pp. 21-28 ◽  
Author(s):  
DD Milovanovic ◽  
JR Milovanovic ◽  
M Radovanovic ◽  
I Radosavljevic ◽  
S Obradovic ◽  
...  

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.


2019 ◽  
Vol 3 (1) ◽  
pp. e000427 ◽  
Author(s):  
Sissel Sundell Haslund-Krog ◽  
Steen Hertel ◽  
Kim Dalhoff ◽  
Susanne Poulsen ◽  
Ulla Christensen ◽  
...  

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.


Author(s):  
Tomohiro Sasaki ◽  
Elin M. Svensson ◽  
Xiaofeng Wang ◽  
Yanlin Wang ◽  
Jeffrey Hafkin ◽  
...  

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.


2007 ◽  
Vol 25 (13) ◽  
pp. 1772-1778 ◽  
Author(s):  
Georg Hempel ◽  
Doris Oechtering ◽  
Claudia Lanvers-Kaminsky ◽  
Thomas Klingebiel ◽  
Josef Vormoor ◽  
...  

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.


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