A number of anatomical and physiological factors determine the pharmacokinetic profile of a drug. Differences in physiology in paediatric populations compared with adults can influence the concentration of drug within the plasma or tissue. Healthcare professionals need to be aware of anatomical and physiological changes that affect pharmacokinetic profiles of drugs to understand consequences of dose adjustments in infants and children. Pharmacokinetic clinical trials in children are complicated owing to the limitations on blood sample volumes and perception of pain in children resulting from blood sampling. There are alternative sampling techniques that can minimize the invasive nature of such trials. Population based models can also limit the sampling required from each individual by increasing the overall sample size to generate robust pharmacokinetic data. This review details key considerations in the design and development of paediatric pharmacokinetic clinical trials.

Paediatric formulation design is complex as there is a need to understand the developmental physiological changes that occur during childhood and their impact on the absorption of drugs. Paediatric dose adjustments are usually based on achieving pharmacokinetic or pharmacodynamic profiles equivalent to those achieved in adult populations. However, differences in the way in which children handle adult products or the use of bespoke paediatric formulations can result in unexpected pharmacokinetic drug profiles with altered clinical efficacy. Differences in drug formulations need to be understood by healthcare professionals involved in the prescribing, administration or dispensing of drugs to children such that appropriate advice is given to ensure that therapeutic outcomes are achieved. This issue is not confined to oral medicines but is applicable for all routes of administration encountered in paediatric therapy.

IntroductionNon-medical prescribing has the potential to deliver innovative healthcare within limited finances. However, uptake has been slow, and a proportion of non-medical prescribers do not use the qualification. This systematic review aimed to describe the facilitators and barriers to non-medical prescribing in the United Kingdom.MethodsThe systematic review and thematic analysis included qualitative and mixed methods papers reporting facilitators and barriers to independent non-medical prescribing in the United Kingdom. The following databases were searched to identify relevant papers: AMED, ASSIA, BNI, CINAHL, EMBASE, ERIC, MEDLINE, Open Grey, Open access theses and dissertations, and Web of Science. Papers published between 2006 and March 2017 were included. Studies were quality assessed using a validated tool (QATSDD), then underwent thematic analysis. The protocol was registered with PROSPERO (CRD42015019786).ResultsOf 3991 potentially relevant identified studies, 42 were eligible for inclusion. The studies were generally of moderate quality (83%), and most (71%) were published 2007–2012. The nursing profession dominated the studies (30/42). Thematic analysis identified three overarching themes: non-medical prescriber, human factors, and organisational aspects. Each theme consisted of several sub-themes; the four most highly mentioned were ‘medical professionals’, ‘area of competence’, ‘impact on time’ and ‘service’. Sub-themes were frequently interdependent on each other, having the potential to act as a barrier or facilitator depending on circumstances.DiscussionAddressing the identified themes and subthemes enables strategies to be developed to support and optimise non-medical prescribing. Further research is required to identify if similar themes are encountered by other non-medical prescribing groups than nurses and pharmacists.

Unused medicines are returned in substantial quantities and have considerable financial value, with many in a condition suitable for re-use. We consider it appropriate to reopen the debate on the potential for re-using these medicines in developing countries where medicines are not widely available and also within the UK.

PROSPERO CRD42015017212. [Noblet T, Marriott J, Graham-Clarke E, Rushton A (2017) Barriers to and facilitators of independent non-medical prescribing in clinical practice: a mixed-methods systematic review. Journal of Physiotherapy 63: 221-234].