Prescribing antiepileptics for the elderly: Differences between guideline recommendations and clinical practice

The incidence of epilepsy in patients aged >60 years is higher than in any other period of life. Yet, until recently, what was known about the treatment of older patients with epilepsy has been inferred from studies in younger patients. A growing body of clinical evidence focused exclusively on the elderly suggests that, while some issues are similar for older and younger adults, older patients with epilepsy may require even more attention regarding antiepileptic drug (AED) selection than younger patients. This article reviews published guidelines and recommendations to identify explicit recommendations for use of specific AEDs in the elderly, and assesses the extent to which those recommendations have been adopted in clinical practice. We found that while one systematically derived guideline stated that lamotrigine may be a good choice for older patients because of its favourable adverse effect profile, only clinical recommendations based on expert opinion explicitly identified AEDs that are more and less appropriate for use in the elderly. Examination of published studies describing recent AED-prescribing patterns suggests that clinical recommendations have been, at best, slowly adopted. This observation is exemplified by the fact that older patients newly diagnosed with epilepsy are still prescribed phenobarbital - a drug identified as suboptimal in 1985. In order to better understand the delay in adopting clinical recommendations, we examine these findings in light of diffusion of innovations theory, a theory that has been used to understand dissemination of other new medical technologies. According to this theory, while it is too early to suggest that use of second-generation AEDs in the elderly has been delayed, the continued use of phenobarbital in older patients newly diagnosed with epilepsy represents a serious delay in adoption of recent guidelines. Delays may be related to lack of knowledge by primary care clinicians and emergency room physicians (who frequently treat older patients with epilepsy), lack of 'opinion leaders' in primary care and perhaps general neurology, clinicians' focus on seizure control as the primary endpoint in treating patients with epilepsy, and difficulties in changing long-standing prescribing patterns. Research targeting barriers to more appropriate prescribing is needed to determine appropriate strategies for changing AED prescribing practices in the elderly.