Trends in antiepileptic drug prescribing for older patients with new-onset epilepsy: 2000-2004

Background: Newer antiepileptic drugs (AEDs) have been shown to be equally efficacious as older seizure medications but with fewer neurotoxic and systemic side effects in the elderly. A growing body of clinical recommendations based on systematic literature review and expert opinion advocate the use of the newer agents and avoidance of phenobarbital and phenytoin. This study sought to determine if changes in practice occurred between 2000 and 2004-a time during which evidence and recommendations became increasingly available. Methods: National data from the Veterans Health Administration (VA; inpatient, outpatient, pharmacy) from 1998 to 2004 and Medicare data (1999 - 2004) were used to identify patients 66 years and older with new-onset epilepsy. Initial AED was the first AED received from the VA. AEDs were categorized into four groups: phenobarbital, phenytoin, standard (carbamazepine, valproate), and new (gabapentin, lamotrigine, levetiracetam, oxcarbazepine, topiramate). Results: We found a small reduction in use of phenytoin (70.6% to 66.1%) and phenobarbital (3.2% to 1.9%). Use of new AEDs increased significantly from 12.9% to 19.8%, due primarily to use of lamotrigine, levetiracetam, and topiramate. Conclusions: Despite a growing list of clinical recommendations and guidelines, phenytoin was the most commonly used antiepileptic drug, and there was little change in its use for elderly patients over 5 years. Research further exploring physician and health care system factors associated with change (or lack thereof) will provide better insight into the impact of clinical recommendations on practice.