Medicines management in children and young people: pharmacokinetics, drug calculations and off-label drug use

Medicines management in children and young people presents specific challenges because children differ from adults in their response to medicines. The way in which medicines work inside the human body, or pharmacokinetics, varies according to age and stage of development. Accurate drug calculations for a child rely on the careful consideration of a series of factors, such as weight and height, pharmacokinetics and drug characteristics. This article focuses on three fundamental aspects: pharmacokinetics, drug calculations, and unlicensed and off-label drug use.

Improved paediatric antimicrobial prescribing with a smartphone application: a before and after interventional study

INTRODUCTION

Children have a high consumption of antimicrobials that require complicated decision-making by prescribers. Despite this, antimicrobial stewardship (AMS) interventions are often not translated into paediatric medicine. Script is a smartphone application (app) launched in Auckland, New Zealand to support decision-making for antimicrobial prescribers. The aim was to improve adherence to existing local clinical guidelines for both adult and paediatric infections.

METHODS

Inpatient and emergency department antimicrobial prescriptions were prospectively collected and evaluated for guideline adherence. Baseline prescribing data were collected and compared with prescribing at 4 months and 1 year after the app was launched. Prescriptions were graded as 'appropriate' or 'inappropriate' by investigators. Grading was done blinded to timing of the prescription relative to the intervention.

RESULTS

Following the launch of the Script app, guideline adherence significantly increased from 241 of 348 (69%) antimicrobial prescriptions graded as appropriate during the baseline period to 301 of 359 (83%) after 4 months (p<0.0001). This improvement from baseline was sustained at 1 year with 263 of 323 (81%) adherence (p<0.001). At 1 year, this improvement could be demonstrated separately for medical, surgical and emergency department prescriptions.

CONCLUSION

There was a significant and sustained improvement in adherence to paediatric antimicrobial guidelines following the introduction of a prescribing support app. The need to seek guidance for antimicrobial doses due to the age-based and weight-based calculations in paediatrics may mean that AMS interventions such as decision support and prescribing tools are particularly well suited to paediatric prescribing.

Oral drug delivery strategies for development of poorly water soluble drugs in paediatric patient population

Selecting the appropriate formulation and solubility-enabling technology for poorly water soluble drugs is an essential element in the development of formulations for paediatric patients. Different methodologies and structured strategies are available to select a suitable approach and guide formulation scientists for development of adult formulations. However, there is paucity of available literature for selection of technology and overcoming the challenges in paediatric formulation development. The need for flexible dosing, and the limited knowledge of the safety of many formulation excipients in paediatric subjects, impose significant constraints and in some instances require adaptation of the approaches taken to formulating these drugs for the adult population. Selection of the best drug delivery system for paediatrics requires an efficient, systematic approach that considers a drug's physical and chemical properties and the targeted patient population's requirements. This review is a step towards development of a strategy for the design of solubility enhancing paediatric formulations of highly insoluble drugs. The aim of this review is to provide an overview of different approaches and strategies to consider in order to assist development of paediatric formulation for poorly water-soluble drugs with the provision of examples of some marketed products. In addition, it provides recommendations to overcome the range of challenges posed by these strategies and adaptations of the adult approach/product presentation required to enable paediatric drug development and administration.

Intestinal giardiasis in children: Five years' experience in a reference unit

BACKGROUND

Giardiasis is highly prevalent in children and is often mildly symptomatic. First-line treatment is metronidazole, but treatment failure is not uncommon. We describe a paediatric series, to identify risk factors for treatment failure and to analyse the safety and effectiveness of other treatment strategies.

METHODS

Retrospective observational study, including children diagnosed with giardiasis from 2014 to 2019. Diagnosis was based on direct visualisation by microscopy after concentration using an alcohol-based fixative, antigen detection and/or DNA detection by polymerase chain reaction in stool. Treatment failure was considered when GI was detected 4 weeks after treatment.

RESULTS

A total of 120 patients were included, 71.6% internationally adopted, median age 4.2 (2.3-7.3) years. Only 50% presented with symptoms, mainly diarrhoea (35%) and abdominal pain (14.1%); co-parasitism was frequent (45%). First-line treatment failure after a standard dose of metronidazole was 20%, lowering to 8.3% when a higher dose was administered (p < 0.001). Quinacrine was administered in 10 patients, with 100% effectiveness. Children <2 years were at higher risk of treatment failure (OR 3.49; 95% CI 1.06-11.53; p = 0.040).

CONCLUSIONS

In children with giardiasis, treatment failure is frequent, especially before 2 years of age. Quinacrine can be considered as a second-line treatment. After treatment, eradication should be confirmed.

Dosing Accuracy of Oral Extemporaneous Suspensions of Antibiotics: Measuring Procedures and Administration Devices

Extemporaneous suspensions are often marketed with several administration devices that can be freely used by patients/caregivers. The homogeneity of suspensions requires shaking before use. Hence, it is crucial to assess the precision of all devices and the users’ awareness of the shaking procedure. This study was conducted at University Institute Egas Moniz with 40 pharmacy students who were asked to measure 2.5 and 5 mL of two extemporaneous azithromycin suspensions. Formulation A is marketed with a double-dosing spoon and oral syringe, whereas B includes a transparent dosing spoon. Both have a reconstitution cup. The user’s preference for administration devices, the degree of compliance with the ‘shake before use’ instruction and the accuracy of the manipulation were assessed. The double-dosing spoon was the preferred device. The “shake before use” instruction was overlooked by most volunteers. The average measured volumes obtained with the double-dosing spoon were significantly different from the ones obtained with the oral syringe (p < 0.001) and significantly lower than the reference dose (p < 0.001). The oral syringe originates significantly higher values than the reference dose (p < 0.001). The dosing spoons values were significantly different from each other (p < 0.001). Liquid medicines containing several administration devices may be a challenge since they are nonequivalent.

Pharmacokinetics and population pharmacokinetics in pediatric oncology

Pharmacokinetic research has become increasingly important in pediatric oncology as it can have direct clinical implications and is a crucial component in individualized medicine. Population pharmacokinetics has become a popular method especially in children, due to the potential for sparse sampling, flexible sampling times, computing of heterogeneous data, and identification of variability sources. However, population pharmacokinetic reports can be complex and difficult to interpret. The aim of this article is to provide a basic explanation of population pharmacokinetics, using clinical examples from the field of pediatric oncology, to facilitate the translation of pharmacokinetic research into the daily clinic.

How to Conduct Clinical Trials in Children: A Tutorial

Despite a growing interest in, and commitment to, implementing pediatric clinical trials, approximately one in every five trials in children fails because of inappropriate study design, suboptimal experiment planning, or inadequate participant enrollment. This tutorial, presented from the perspectives of seasoned pediatric investigators, an experienced research coordinator, and an established pediatric clinical trials network, is designed to provide practical guidance for successfully implementing pediatric clinical trials at an academic center or another comparable institution.