Prioritizing children's medicines for research: A pharmacoepidemiological study of antiepileptic drugs

Abstract

Aims: To investigate the prescribing epidemiology, in UK primary care, of newer antiepileptic drugs (AEDs) compared with conventional AEDs and to identify AEDs for further research in response to the European Medicines Agency report on epilepsy. Methods: Subjects aged 0-18 years, from the UK General Practice Research Database, who were prescribed an AED between 1993 and 2005. Prescribing prevalence and incidence, stratified by age and AED, were calculated. Results: A total of 7721 subjects were included and 70% were prescribed one drug. Overall prescribing prevalence for all AEDs had increased by 19%. The prevalence (95% confidence interval) of newer AED prescribing had increased fivefold from 0.67 (0.58, 0.76) to 3.20 (3.03, 3.37) per 1000 person-years. Conversely, the prevalence of conventional AEDs had declined by 17% from 6.63 (6.34, 6.92) per 1000 person-years to 5.51 (5.28, 5.73). Lamotrigine had 65% of newer AED prescriptions and was the most prescribed newer drug for both the 2-11 years and 12-18 years age groups with prevalences of 1.47 and 2.55 per 1000 person-years, respectively. Conclusions: There is a rapid increase in newer AED prescribing to children and adolescents in UK primary care, while prescribing of conventional AEDs is declining. Since 1997, the prevalence of vigabatrin has fallen, coinciding with the UK safety warnings on visual field defects. The uptake of lamotrigine, topiramate and levetiracetam is rapid and as the safety of these drugs has not been established, they should be prioritized for further research. Following concerns with vigabatrin, long-term safety surveillance of all newer AEDs is strongly recommended. © 2007 The Authors.