Population pharmacokinetics of ceftazidime in critically ill children: impact of cystic fibrosis

Dose optimization of β-lactam antibiotics in children: from population pharmacokinetics to individualized therapy

INTRODUCTION

β-Lactams are the most widely used antibiotics in children. Their optimal dosing is essential to maximize their efficacy, while minimizing the risk for toxicity and the further emergence of antimicrobial resistance. However, most β-lactams were developed and licensed long before regulatory changes mandated pharmacokinetic studies in children. As a result, pediatric dosing practices are poorly harmonized and off-label use remains common today.

AREAS COVERED

β-Lactam pharmacokinetics and dose optimization strategies in pediatrics, including fixed dose regimens, therapeutic drug monitoring, and model-informed precision dosing are reviewed.

EXPERT OPINION/COMMENTARY

Standard pediatric doses can result in subtherapeutic exposure and non-target attainment for specific patient subpopulations (neonates, critically ill children, e.g.). Such patients could benefit greatly from more individualized approaches to dose optimization, beyond a relatively simple dose adaptation based on weight, age, or renal function. In this context, Therapeutic Drug Monitoring (TDM) and Model-Informed Precision Dosing (MIPD) emerge as particularly promising avenues. Obstacles to their implementation include the lack of strong evidence of clinical benefit due to the paucity of randomized clinical trials, of standardized assays for monitoring concentrations, or of adequate markers for renal function. The development of precision medicine tools is urgently needed to individualize therapy in vulnerable pediatric subpopulations.

Therapeutic drug monitoring-guided dosing for pediatric cystic fibrosis patients: recent advances and future outlooks

INTRODUCTION

Medicine use in children with cystic fibrosis (CF) is complicated by inconsistent pharmacokinetics at variance with the general population, a lack of research into this and its effects on clinical outcomes. In the absence of established dose regimens, therapeutic drug monitoring (TDM) is a clinically relevant tool to optimize drug exposure and maximize therapeutic effect by the bedside. In clinical practice though, use of this is variable and limited by a lack of expert recommendations.

AREAS COVERED

We aimed to review the use of TDM in children with CF to summarize recent developments, current recommendations, and opportunities for future directions. We searched PubMed for relevant publications using the broad search terms "cystic fibrosis" in combination with the specific terms "therapeutic drug monitoring (TDM)" and "children." Further searches were undertaken using the name of identified drugs combined with the term "TDM."

EXPERT OPINION

Further research into the use of Bayesian forecasting and the relationship between exposure and response is required to personalize dosing, with the opportunity for the development of expert recommendations in children with CF. Use of noninvasive methods of TDM has the potential to improve accessibility to TDM in this cohort.

Beta-Lactams Therapeutic Monitoring in Septic Children-What Target Are We Aiming for? A Scoping Review

The antimicrobial therapy of sepsis and septic shock should be individualized based on pharmacokinetic/pharmacodynamic (PK/PD) parameters to deliver effective and timely treatment of life-threatening infections. We conducted a literature scoping review to identify therapeutic targets of beta-lactam antibiotics in septic pediatric patients and the strategies that have been applied to overcome sepsis-related altered pharmacokinetics and increase target attainment against susceptible pathogens. A systematic search was conducted in the MEDLINE, EMBASE and Web of Science databases to select studies conducted since 2010 with therapeutic monitoring data of beta-lactams in septic children. Last searches were performed on 02 September 2021. Two independent authors selected the studies and extracted the data. A narrative and qualitative approach was used to summarize the findings. Out of the 118 identified articles, 21 met the eligibility criteria. Population pharmacokinetic modeling was performed in 12 studies, while nine studies reported data from bedside monitoring of beta-lactams. Most studies were conducted in the United States of America (n = 9) and France (n = 5) and reported PK/PD data of amoxicillin, ampicillin, azlocillin, aztreonam, cefazolin, cefepime, cefotaxime, ceftaroline, ceftazidime, doripenem, meropenem and piperacillin/tazobactam. Therapeutic targets ranged from to 40% fT> MIC to 100% fT> 6 × MIC. Prolonging the infusion time and frequency were most described strategies to increase target attainment. Monitoring beta-lactam serum concentrations in clinical practice may potentially maximize therapeutic target attainment. Further studies are required to define the therapeutic target associated with the best clinical outcomes.