The EU has issued new regulations on prescribing medicines for children. Sylvia Thompson reports
More than 50 per cent of the medicines used to treat children across Europe have not been tested for use in children and are not authorised for use in children.
This stark statistic has resulted principally from the fact that the majority of clinical trials for new drugs are carried out on adults only and doctors therefore have to use many drugs "off-label" in smaller doses when prescribing medicines for children. Off-label use is when a drug is prescribed at a different dose or frequency in a different age group or for a different condition than that recommended by the pharmaceutical company.
Writing in the Irish Medical Journal recently, editor Dr John Murphy said there was considerable evidence that inaccuracies in drug prescribing for children had resulted in worsening of symptoms and, in some cases, death.
"The risk of error is compounded by the need for additional calculations to determine the dose, particularly the misplacement of decimal points," writes Dr Murphy.
One study of five European hospitals found that 39 per cent of drugs prescribed to children were off-label and a further 7 per cent were unlicensed.
Another study of admissions to neonatal and paediatric intensive care units found a miscalculation rate for medicines of one per 6.8 admission.
General practitioners and hospital paediatricians are aware of the problems of prescribing medicines for children. Colin Bradley, professor of general practice at University College Cork, explains: "Antibiotics are the most commonly prescribed medicines used in children and they have a wide therapeutic window in that one can use them over quite a range and come to no harm."
General practitioners will, according to Prof Bradley, look to hospital paediatricians for a lead when prescribing drugs for asthma, epilepsy or diabetes.
In Britain, the recently published British National Formulary for Children (BNFc) has been welcomed as an important milestone in the administration of medication to children. Distributed in Britain to health professionals free, the BNFc gives information on drug doses and formulations for children and discusses off-licence prescribing issues. It covers children from birth to 16 years.
Prof Bradley says the BNFc is a valuable publication for Irish doctors. "I would like to see it provided free to Irish doctors. The BNF is available free on the web but the BNFc isn't."
Prof Bradley is concerned that in Ireland, it is almost impossible to get independent advice on medicines for children. "In the UK, the norm is to seek information from independent sources - such as the Drug and Therapeutics Bulletin, published by the British Consumers Association - but, in Ireland, most doctors can only rely on industry sources who can't give comparative advice and who will underplay adverse effects of medications," he explains.
The proposed EU regulation on medicines for children will change things dramatically. The regulation, which is expected to become law in 2007, will make it mandatory for pharmaceutical companies to carry out clinical trials on children before a new drug goes on the market. It will also require pharmaceutical companies to carry out clinical trials on children before applying for a licence for drugs currently on the market.
The Irish Medicines Board was involved in the initial drafting of the legislation on medical products for use in children and welcomes the proposed measures. An IMB spokeswoman says: "The fact that this legislation will stimulate paediatric clinical trials will result in the provision of medicines that are geared specifically towards children and so will be of benefit to them.
"Drugs act differently in children compared to adults and children also respond differently which has consequences in terms of effectiveness and side effects."
In the United States, the requirement for new drugs to be studied in children became law with the passing of the Paediatric Research Equity Act in 2003. Since then, the Food and Drug Authority has requested over 660 studies. The European regulation on medicines for children already includes proposals for an EU network of investigators and trial centres to conduct research and development on medicines for children.
The future looks brighter in that research will bring much needed evidence to show which medicines are most appropriate for children, in what dosage and frequency. However, when a wider range of drugs licensed for use in children becomes available, the clinical expertise and prudence of health professionals will be even more important in making decisions for sick children.