Common Medicines ‘Can Harm Children Through Overdosing’

By JULIE WHELDON

MEDICINES given to children could expose them to dangerous overdoses, a study has shown.

Scientists in the U.S. have found that children’s bodies may break down drugs differently to adults, which could increase their risk of experiencing harmful side-effects.

When we are prescribed drugs, proteins in our bodies react with them and break them down.

But the researchers found that babies and young children have lower levels than adults of some major proteins.

As a result, they may break down drugs too slowly and be subjected to a higherthanintended dose.

The researchers studied 240 liver samples taken from a range of ages, from newborns to 18-year-olds.

They looked at levels of enzymes involved in processing drugs in the body.

The results revealed differences between adults and children in a range of proteins.

For one enzyme, a child aged one or two had between 20 and 50 per cent of the amount found in an adult.

But for another, half the children had the same level as an adult.

Scientists from the Medical College of Wisconsin presented their findings at the annual conference of the American Association for the Advancement of Science in St Louis, Missouri.

They said the finding is ‘the strongest and most compelling evidence to date’ of the way children’s ability to break down drugs alters.

Last night, British doctors called for more research into the effects of medicines on children.

Sharon Conroy, a lecturer in paediatric clinical pharmacy at the University of Nottingham, said: ‘For most drugs, we know which enzymes they are metabolised by. If this study can tell us whether they are present in low or excessive amounts, it could give us more information to predict how a child might react to a medicine.

‘That could be particularly useful for new drugs.’ She added that using medicines on children which have only been tested on adults is of concern.

However, doctors often have no alternative but to use them, she said.

‘We do have to extrapolate from adult studies on the use of a drug and have only basic information to predict how a child might react to it.

‘Proper studies are needed on all medicines we use in children.’ The researchers also found one enzyme remained at constant levels while a child was in the womb and after birth.

Another was highest in the first three months in the womb, but then declined steadily. One protein was found to be missing during the first stage of pregnancy. It then built up at varying rates during the first four months of life.

When the child was one, it matched adult levels.

Lead researcher Ronald Hines, a professor of paediatrics at the Children’s Research Institute, part of the Medical College of Wisconsin, said: ‘The dramatic changes observed in enzyme expression must be considered when examining issues of drug effectiveness and safety during early life stages.’

The findings follow a report this month which warned that nine out of ten medicines used on newborn babies have not been tested on children. About half of all prescription and over-the counter drugs given to under-18s have not been put through suitable trials, the report, by a House of Lords EU subcommittee on social policy and consumer affairs warned.

It called for ‘overwhelming and urgent’ action to protect Britain’s 13million children over fears that the untested drugs could be causing harm.

The report said pharmaceutical companies are reluctant to carry out testing on children because of the cost. This left doctors with no alternative but to estimate correct doses based on a child’s height, weight and symptoms.

Baroness Walliswood, chairman of the committee, said the findings would be a concern for all parents.

‘Children are not simply small adults and it cannot be right that 90 per cent of the medication given to newborn babies has only ever been tested on adults,’ she said.

j.wheldon@dailymail.co.uk