An appreciable number of general practitioners' prescriptions for children are for drugs used outside their product licences, say researchers from the University of Nottingham.
This off-label prescribing by GPs reflects inadequacies of the product licence with respect to children, rather than hazardous prescribing practices, they suggest.
The researchers, led by Dr John McIntyre (academic division of child health) examined the prescribing records for 1997 for one suburban general practice in the Midlands. Over the study period, the practice records showed that 1,175 children received at least one prescription. There were 3,347 prescription items, involving 160 different drugs. The researchers found that few prescriptions were for unlicensed drugs (0.3 per cent) but that 10.5 per cent of items were for drugs used off-label.
The most frequently prescribed off-label drugs were systemic antibiotics. Of 677 prescriptions for this class of drug, 106 (16 per cent) were prescribed outside of their product licence and 101 of these were off-label for dose. In 88 of these prescriptions, doses were lower and in 10 they were higher than recommended. The remainder were at non-recommended dosing intervals.
The researchers point out that amoxicillin and ampicillin both have one licensed dose recommendation for children aged up to 10 years and, as it is common practice to adjust doses according to the weight of a child, prescriptions would fall outside the licence recommendations.
Other groups of drugs found to be commonly prescribed off-label were anti-asthmatics and emollients. The off-label prescribing of inhaled corticosteroids was probably due to licensed doses not being in accordance with the current British Thoracic Society guidelines, comment the researchers.
They conclude that there are shortfalls in the current licensing framework for the use of drugs in children and that GPs who are anxious to write safe and effective prescriptions for children cannot rely on product information. The study is published in Archives of Disease in Childhood (2000;83:498).