A renewed call for testing the safety and efficacy of epileptic medicines in children has been made after researchers found that doctors are issuing more and more prescriptions for the latest generation of anti-epilepsy drugs to patients aged under 18.

Professor Ian Wong, from the Centre for Paediatric Pharmacy Research at the University of London, and his team looked at the prescribing trends of newer antiepileptic drugs (AEDs) in primary care compared with conventional ones, in subjects aged up to 18 years old over a period 13 years.

Their findings, published in the British Journal of Pharmacology, showed that, overall, prescribing prevalence for all AEDs had climbed 19% in the period 1993 to 2005 but, interestingly, newer AED scripts had increased fivefold while traditional therapies slid 17%. According to the researchers, GlaxoSmithKline’s Lamictal (lamotrigine) had 65% of newer AED prescriptions, and was the top scorer in both the two–11 years and 12–18 years subgroups, but Johnson & Johnson’s Topamax (topiramate) and UCB’s Keppra (levetiracetam) were also on the rise.

The problem with this swelling uptake of these medicines is that, while they have been rigorously tested in adults, their safety has not been established in children. Moreover, dosing regimens are based on adult patients, and so doctors need to estimate the correct amount for children. Therefore, the latest generation of AEDs should be prioritised for further research, the study authors say, and they ‘strongly’ recommend long-term surveillance of the paediatric use of these medicines.

Tighter regulations

Earlier this year, the European Union Regulation on Paediatric Medicines came into force, marking an attempt to provide children with better and safer access to medicines. The rule is designed to encourage high-quality paediatric research and also means that any new drug licensed in Europe must be explored for its potential use in children.

This is the first time specific legislation has been passed in the EU that regulates pharmaceutical research involving children - an area that has often been overlooked by drugmakers because of the small market, the challenges of undertaking trials in children and the high development costs. Now, companies that do conduct trials on new drugs will be offered incentives in the form of patent extensions of six months, rising to two years for 'orphan' drugs with a limited patient population. A new body, the Paediatric Committee, sited at the European Medicines Agency, will be set up to oversee testing.