Children 'under-dosed' on penicillin
Millions of children in the UK are being given penicillin at too low a dose, putting them at risk of persistent infections, say researchers.
They looked at 65,000 prescriptions given to some 46,000 children in 2010.
About two-thirds of those aged six to 18 were given suboptimal doses.
The researchers said most of them would still get better but some could develop complications - though the study published in the British Journal of General Practice did not look at this.
The UK work, involving researchers from King's College London and Imperial College London, examined GP prescriptions of oral penicillin drugs, the most commonly prescribed antibiotics for children worldwide.
While nearly all children aged one to five received the recommended dose for their age, 40% of six to 12-year-olds and 70% of 12 to 18-year-olds were given lower doses than those set out in the prescribing manual the British National Formulary for Children.
The study authors say prescribing practices needed to be reviewed, especially since youngsters are getting heavier and may need larger doses as a result.
And GPs are not necessarily to blame - the paediatric dosing guidelines have remained complicated, with the potential to confuse prescribers, they say.
'More health contacts'
The British National Formulary for Children recommends different doses of penicillin depending on the individual drug and the condition being treated. For some conditions it gives a dose recommendation by weight, for others it is by age group.
Dr Sonia Saxena, co-author from Imperial College London who is also a GP, said: "It is important now to understand why GPs are prescribing sub-therapeutic levels of penicillin. Some GPs may be erring on the side of caution, prescribing low doses to avoid errors or side-effects.
"In the majority of cases children will still get better, but under-treating those children who do need antibiotics could mean more infectious complications and more health contacts overall."
Inappropriate use of antibiotics also increases the chance of drug resistance developing.
Steve Tomlin of the Royal Pharmaceutical Society said the research raised important questions, but did not provide the answers.
"It raises the fundamental question about whether we are dosing appropriately for children based on age. Perhaps we need to be looking at the individual weight of a child and dosing accordingly, but those sorts of calculations can go wrong and are not without risk.
"The way forward is not clear. We need to look at the dosing bands and see if they are right or if they need to change."