scholarly journals Contribution of Population Pharmacokinetics of Glycopeptides and Antifungals to Dosage Adaptation in Paediatric Onco-hematological Malignancies: A Review

2021 ◽  
Vol 12 ◽  
Author(s):  
Stéphanie Leroux ◽  
Françoise Mechinaud-Heloury ◽  
Evelyne Jacqz-Aigrain
Keyword(s):  
Hematological Malignancies ◽  
Age Groups ◽  
Population Pharmacokinetic ◽  
Pharmacokinetic Studies ◽  
Immunocompromised Patients ◽  
Main Study ◽  
Specific Patient ◽  
Study Characteristics ◽  
Dosing Optimization ◽  
Short Presentation

The response to medications in children differs not only in comparison to adults but also between children of the different age groups and according to the disease. This is true for anti-infectives that are widely prescribed in children with malignancy. In the absence of pharmacokinetic/pharmacodynamic paediatric studies, dosage is frequently based on protocols adapted to adults. After a short presentation of the drugs, we reviewed the population pharmacokinetic studies available for glycopeptides (vancomycin and teicoplanin, n = 5) and antifungals (voriconazole, posaconazole, and amphotericin B, n = 9) currently administered in children with onco-hematological malignancies. For each of them, we reported the main study characteristics including identified covariates affecting pharmacokinetics and proposed paediatric dosage recommendations. This review highlighted the very limited amount of data available, the lack of consensus regarding PK/PD targets used for dosing optimization and regarding dosage recommendations when available. Additional PK studies are urgently needed in this specific patient population. In addition to pharmacokinetics, efficacy may be altered in immunocompromised patients and prospective clinical evaluation of new dosage regimen should be provided as they are missing in most cases.

scholarly journals Hierarchy of evidence in interpretation of clinical significance of drug interactions

2012 ◽  
Vol 65 (1-2) ◽  
pp. 45-49
Author(s):  
Bozana Nikolic ◽  
Miroslav Savic
Keyword(s):  
Drug Metabolism ◽  
Drug Interactions ◽  
Clinical Significance ◽  
Health Professionals ◽  
Molecular Entity ◽  
Population Pharmacokinetic ◽  
Pharmacokinetic Studies ◽  
Potential Interactions

Introduction. Since drug interactions may result in serious adverse effects or failure of therapy, it is of huge importance that health professionals base their decisions about drug prescription, dispensing and administration on reliable research evidence, taking into account the hierarchy of data sources for evaluation. Clinical Significance of Potential Interactions - Information Sources. The sources of data regarding drug interactions are numerous, beginning with various drug reference books. However, they are far from uniformity in the way of choosing and presenting putative clinically relevant interactions. Clinical Significance of Potential Interactions - Interpretation of Information. The difficulties in interpretation of drug interactions are illustrated through the analysis of a published example involving assessment made by two different groups of health professionals. Systematic Evaluation of Drug-Drug Interaction. The potential for interactions is mainly investigated before marketing a drug. Generally, the in vitro, followed by in vivo studies are to be performed. The major metabolic pathways involved in the metabolism of a new molecular entity, as well as the potential of induction of human enzymes involved in drug metabolism are to be examined. In the field of interaction research it is possible to make use of the population pharmacokinetic studies as well as of the pharmacodynamic assessment, and also the postregistration monitoring of the reported adverse reactions and other literature data. Conclusion. In vitro and in vivo drug metabolism and transport studies should be conducted to elucidate the mechanisms and potential for drug-drug interactions. The assessment of their clinical significance should be based on well-defined and validated exposure-response data.

scholarly journals Population Pharmacokinetic Study of Ceftriaxone in Elderly Patients, Using Cystatin C-Based Estimates of Renal Function To Account for Frailty

2020 ◽  
Vol 64 (10) ◽  
Author(s):  
Shu Jin Tan ◽  
Matthew Cockcroft ◽  
Madhu Page-Sharp ◽  
Glenn Arendts ◽  
Timothy M. E. Davis ◽  
...  
Keyword(s):  
Renal Function ◽  
Elderly Patients ◽  
Cystatin C ◽  
Pharmacokinetic Study ◽  
Severe Renal Impairment ◽  
Population Pharmacokinetic ◽  
Pharmacokinetic Studies ◽  
Total Exposure ◽  
Population Pharmacokinetic Study ◽  
Trough Concentrations

ABSTRACT Ceftriaxone is widely used for respiratory and urinary infections in elderly and frail patients, but there are few pharmacokinetic studies. A prospective population pharmacokinetic study of ceftriaxone in adults over 65 years old was undertaken. Dried blood spots collected at baseline (predose) and 0.5, 1, 4, 8, and 24 h after administration of 1 g of ceftriaxone were assayed using a validated liquid chromatography-mass spectroscopy analytical method. Frailty was classified using the Edmonton frailty scale and grip strength via a hand dynamometer. Estimates of glomerular filtration rate were determined using creatinine-based and cystatin C-based equations. Of 26 patients recruited, 23 (88%) were vulnerable or very frail. Estimates of drug clearance improved significantly with a cystatin C-based estimate of renal function that accounted for frailty. Simulations indicate that the combined effects of ranges of size and renal function resulted in a 6-fold range in peak ceftriaxone concentrations and 9-fold range in total exposure (area under the concentration-time curve [AUC]). For elderly patients with moderate or severe renal impairment, 48-h dosing results in greater trough concentrations and total exposure than the trough concentrations and total exposure in patients with normal renal function receiving 24-h dosing. Cystatin C-based measures of renal function improved predictions of ceftriaxone clearance in elderly patients.

scholarly journals 1558. A Population Pharmacokinetic Model for Posaconazole Intravenous Solution and Oral Powder for Suspension Formulations in Pediatric Patients With Neutropenia

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S569-S569
Author(s):  
Gregory A Winchell ◽  
Rik de Greef ◽  
Rebecca E Wrishko ◽  
Eric Mangin ◽  
Hetty Waskin ◽  
...  
Keyword(s):  
Goodness Of Fit ◽  
Geometric Mean ◽  
Age Groups ◽  
Invasive Fungal Disease ◽  
Population Pharmacokinetic ◽  
Once Daily ◽  
Intravenous Solution ◽  
Backward Procedure ◽  
Using Data ◽  
The Impact

Abstract Background Posaconazole is approved in adults for prophylaxis and treatment of invasive fungal disease. Two formulations that offer weight-based dosing—intravenous (IV) and oral powder for suspension (PFS)—are being evaluated in children. A population pharmacokinetic (popPK) approach was used to characterize and predict the PK exposure of posaconazole PFS and IV formulations in children to identify dosages associated with achieving a target PK of 1200 ng/mL as the mean Cavg and individual Cavg ≥500 ng/mL and <2500 ng/mL in ~90% of patients. Methods A popPK model was developed through nonlinear mixed-effects modeling using data obtained from a trial in children with neutropenia (ClinicalTrials.gov, NCT02452034; Merck protocol, MK-5592-097). Three dose cohorts (3.5, 4.5, and 6 mg/kg/day [≤300 mg/day]) were studied in two age groups (2–<7 years and 7–17 years). Posaconazole IV was administered twice on day 1 then once daily through at least day 10, followed by PFS once daily through day 28 at clinician discretion. A compartmental model, including both formulations, was fit to the data. Model selection was based on the Log-Likelihood Criterion, goodness-of-fit plots, and scientific plausibility. Significance of the covariates was assessed in a stepwise forward inclusion/backward procedure. An additional assessment characterized the impact of different food covariates on bioavailability. Results An open one-compartmental PK model with first-order absorption and estimated bioavailability, as well as allometrically scaled effects of body weight on clearance and volume, adequately described the PK of posaconazole IV and PFS formulations. Model predictions are shown in the Table. Effects of the different food covariates were not statistically significant. Simulations indicated that for the 6-mg/kg/d dose, model-predicted Cavg generally met PK targets. Model-predicted Cavg was ≥500 ng/mL in >90% of subjects in all cohorts. The 1200-ng/mL target geometric mean Cavg was achieved for all but the 2–<7 years cohort receiving the PFS formulation. Conclusion This popPK-based analysis demonstrated that the 6-mg/kg/d dose of IV or PFS posaconazole formulation (≤300 mg/days) is appropriate for children (2–17 years) and that PFS can be administered without regard to food. Disclosures All authors: No reported disclosures.

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