Variability in clinical pharmacology of drugs in children

Bridging the Worlds of Pharmacometrics and Machine Learning

Precision medicine requires individualized modeling of disease and drug dynamics, with machine learning-based computational techniques gaining increasing popularity. The complexity of either field, however, makes current pharmacological problems opaque to machine learning practitioners, and state-of-the-art machine learning methods inaccessible to pharmacometricians. To help bridge the two worlds, we provide an introduction to current problems and techniques in pharmacometrics that ranges from pharmacokinetic and pharmacodynamic modeling to pharmacometric simulations, model-informed precision dosing, and systems pharmacology, and review some of the machine learning approaches to address them. We hope this would facilitate collaboration between experts, with complementary strengths of principled pharmacometric modeling and flexibility of machine learning leading to synergistic effects in pharmacological applications.

Potential clinical impact of taking multiple blood samples for research studies in paediatric oncology: how much do we really know?

Pharmacological studies of anti-cancer agents in children are essential to determine their clinical safety and efficacy, both of which can differ considerably from that observed in adults. However, the potential clinical impact of taking blood samples, in addition to those required for standard clinical practice is commonly a concern for both medical and allied staff and parents. Frequently quoted 'safe limits' of 3%-5% of total blood volume taken on any one study day are not based on published data and may not be acceptable for all patients. This article reviews some of the reasons why clinical pharmacology data for anti-cancer drugs is often lacking in a paediatric patient population, summarises data from a retrospective study investigating the potential impact of repeated blood sampling for research purposes and discusses how this issue may be more systematically addressed in future studies. Research involving children with cancer should be limited to those studies addressing key scientific questions and should be designed to limit both the number and volume of blood samples required.

Antibacterial agents in pediatrics

Antibiotics are among the most widely prescribed therapeutic agents in children. Several new trends in antibiotic usage for pediatric care have emerged. New mechanisms of antibacterial resistance have required a broader repertoire of antibiotic usage, including new agents directed at multidrug resistance. After promotion of judicious antibiotic use, there has been a decline in the number of pediatric prescriptions for antibiotics. Recent legislation addresses the necessity for pediatric clinical drug trials, ensuring development of further antibacterial agents for use in pediatric patients.

Antibacterial agents in pediatrics

From low birth weight infants to adolescents, physiologic and developmental differences underlie the marked differences in pharmacokinetics and pharmacodynamics of antibacterial agents. Certain diseases, such as cystic fibrosis, also can alter these parameters. This article describes the principles of pharmacokinetics and pharmacodynamics that are unique to children and that characterize the clinical application of selected antibacterial agents to infectious diseases in children.

Influence of maturation and growth on cefetamet pivoxil pharmacokinetics: rational dosing for infants

The pharmacokinetics of intravenous (i.v.) cefetamet and the bioavailability of oral cefetamet pivoxil in infants aged 3.5 to 17.3 months who were hospitalized for urological surgery were characterized. The absorption of cefetamet pivoxil administered in a syrup formulation was 38 +/- 19% (n = 5) for infants, which was comparable to values observed for children and adults. The plasma half-life of i.v. cefetamet was 3.03 +/- 0.96 h (mean +/- standard deviation; n = 20) in the infants. This was not different from the value observed for normal adult subjects but was longer than that reported for children aged 3 to 12 years. Urinary recovery of cefetamet after i.v. administration to infants was 63.4 +/- 17.7% (n = 16), which was less than the 80% recovery found in older children and adults. The steady-state volume of distribution was 399 +/- 116 ml/kg of body weight. It was comparable in size and showed the same dependence on body weight as it did in children and adults. The mean systemic clearance per kilogram of body weight in the infants was lower than that in children and adults, apparently because of immaturity of clearance processes. A model that accounted for maturation and growth with increasing age was developed for the clearance. On the basis of this model, the clearance capacity increased from birth to 5 years by a factor of 4.5 because of maturation. Maturation progressed exponentially, with a half-life of 14 months. This model was used to develop dosing regimen guidelines for pediatric patients aged 3.5 months and older.