Dosing of oral penicillins in children: is big child=half an adult, small child=half a big child, baby=half a small child still the best we can do?

Abstract

The improving Children’s Antibiotic Prescribing UK Research Network thinks it’s time to abandon this historical rule of thumb

Oral penicillin prescribing for children in the UK: a comparison withBNF for Childrenage-band recommendations

“…It is important that GPs are aware that these age-bands were devised many years ago and therefore the relative mg/kg dosing has changed and reduced over time in relation to the average weights of children today. 6 This impact is compounded by the fact that when the adult doses of these penicillins were increased, these dose increases were never reflected in the paediatric dosing recommendations. 6 A detailed qualitative assessment of current prescriber practice is required to understand reasons for the use of age-bands and barriers to medical implementation of weight-based dosing regimens.…”

“…6 This impact is compounded by the fact that when the adult doses of these penicillins were increased, these dose increases were never reflected in the paediatric dosing recommendations. 6 A detailed qualitative assessment of current prescriber practice is required to understand reasons for the use of age-bands and barriers to medical implementation of weight-based dosing regimens. For example, it may be that apparently subtherapeutic doses are issued in the recognition that most infections are self-limiting; or that GPs are concerned about the risk of side effects with higher doses.…”

“…Given the recent call to apply the evidence that interactive electronic tools to improve GP antibiotic prescribing among children are most effective when both parents and GPs are in consultation, it would be a relatively simple step to incorporate computer-based alerts to incorrectly prescribed antibiotic doses calculated on a child's weight-band or age-band into electronic prescribing formularies. 17 The study also recommends that the evidence base for the paediatric dosing of oral penicillins, which is historical, 6 is strengthened through pharmacokinetic and/or pharmacodynamic studies to identify optimum dosing of these off-patent but crucially important antimicrobials for the treatment of common infectious diseases in children of different ages. While the majority of these studies to date are undertaken in secondary care settings, the opportunities to use novel pharmacokinetic methods, including population-based modelling, will facilitate the conduct of such investigations in primary care in the future.…”

“…This format -with multiple methods presented, each providing different ways to identify an 'appropriate' dose -gives the paediatric dosing guidelines potential ambiguity, which may confuse prescribers. However, many UK GPs routinely use the age-band dosing, first introduced in 1963, 6,8 which allows rapid selection of the appropriate dose as recommended for the age of the child. This study aimed to analyse oral penicillin prescribing practices by GPs in…”

“…5 The BNFC oral penicillin paediatric dosing recommendations have remained largely unchanged for many decades; this is despite increases in the recommended adult doses of oral penicillins over this period, as well as the changing prevalence of childhood obesity and antimicrobial resistance. 6,7 The BNFC recommends dosing oral penicillins in children according to age-bands, weightbands, or weight-based calculations, and to double the dose in severe illness. This format -with multiple methods presented, each providing different ways to identify an 'appropriate' dose -gives the paediatric dosing guidelines potential ambiguity, which may confuse prescribers.…”