Abstracts

Rationale: We previously reported on antiepileptic (AED) prescribing patterns for the treatment of geriatric epilepsy within the VA from 2000-2004 [Pugh MJ Neurology 2008; 70:2171-2178]. Phenytoin remained the most commonly used AED with a significant increase in the use of the newer AEDs over 5 years. We hypothesized that the pattern of prescribing would change based on recent publications addressing the selection of AED therapy in older adults, changes in the VA pharmacy formulary and an increased availability of IV formulations. Methods: Using an algorithm that was previously validated, we used national data from the VA Administration (inpatient, outpatient and pharmacy) and Medicare data to identify patients 66 years and older with new-onset epilepsy based on ICD-9 Codes. Initial AED monotherapy was the first AED received from the VA. AEDs were categorized into four groups: phenobarbital, phenytoin, standard (carbamazepine and valproate) and new (gabapentin, lamotrigine, levetiracetam, oxcarbazepine and topiramate). Results: (TABLE) In comparison to our previous findings, the use of phenytoin dropped dramatically and phenobarbital use is approaching extinction. With the exception of gabapentin the use of the new AEDs increased, most dramatically for levetiracetam. Conclusions: The use of the older AEDs has declined more rapidly within the past two years. Despite lack of FDA approval or recommendation by the AES, AAN or the ILAE for the use of levetiracetam monotherapy for the treatment of new onset epilepsy, levetiracetam prescribing has dramatically increased compared to all other AEDs in the VA geriatric population. The availability of an IV formulation, ease of use, and lack of associated serious adverse events and potential drug interactions likely contribute to levetiracetam's increased usage.