Prescribing pattern of anti-epileptic drugs in an Italian setting of elderly outpatients: A population-based study during 2004-07

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT • In the last years there has been a growing trend in anti-epileptic drug (AED) use, particularly in elderly patients, but few data concerning indication of use are available in general practice. • Various AEDs, including newer agents, have been approved for indications other than epilepsy and are increasingly also used for unlicensed indications. • No data about the impact of re-imbursement restrictions on the choice of anti-epileptic drugs in general practice are available. WHAT THIS STUDY ADDS • In general practice, a rapid increase of AED prescriptions in the elderly was observed, principally due to the use of newer AEDs for indications other than epilepsy. • Re-imbursement restrictions influenced newer AED use, particularly pregabalin and gabapentin prescriptions. • Phenobarbital, accounting for more than 50% of total AED volume, was the most prescribed medication during the entire study period. This finding should be considered in light of the potential risks associated with phenobarbital use in the geriatric population. AIMS The aims of the study were to assess the trend of older and newer anti-epileptic drugs (AEDs) in the elderly population and to analyze the effects of a health-policy intervention with regard to AED use in general practice in a setting in Southern Italy. METHODS Data were extracted from the 'Caserta-1' Local-Health-Unit Arianna database in the years 2004-07. Patients aged over 65 years, receiving at least one AED prescription and registered in the lists of 88 general practitioners, were selected. The use of older and newer AEDs was calculated as 1 year prevalence and incidence of use and defined daily dose (DDD) per 1000 inhabitants day^-1. Sub-analyses by gender, age and indication of use were performed. RESULTS Most of AED users were treated because of neuropathic pain (64.8%). However, the main indication of use for older AEDs (57.8%) was epilepsy, whereas newer AEDs (79.5%) were used for neuropathic pain. Prevalence and incidence of newer AED use increased until 2006, followed by a reduction in 2007. Newer AEDs, particularly gabapentin and pregabalin, were used in the treatment of more patients than older AEDs. However phenobarbital, accounting for more than 50% of total AED volume, was the most prescribed medication during the entire study period. CONCLUSIONS An increasing use of AEDs has been observed during 2004-07, mostly due to the prescription of newer compounds for neuropathic pain. The fall in the use of newer AEDs during 2007 coincides with revised re-imbursement criteria for gabapentin and pregabalin. The large use of phenobarbital in the elderly should be considered in the light of a risk of adverse drug reactions.