DURHAM, NC – Despite the availability of newer therapies, phenytoin remains the most prescribed antiepileptic drug (AED) within the VHA, according to a recent study.
Researchers from the Southeast Epilepsy Centers of Excellence at the Durham, NC, VAMC and Duke University also found that older veterans are more likely to use the traditional medications than their younger cohorts. The study was presented recently at the American Academy of Neurology 2014 Annual Meeting in Philadelphia.1
Study authors said they sought to identify usage trends of AEDs at the VHA, including whether patient age influences the choice or number of AEDs prescribed.
During fiscal year 2011 — Oct. 1, 2010, to Sept. 30, 2011 — AEDs were prescribed to about 74,000 veterans with a seizure diagnosis, according to the study, which notes, “Understanding which AEDs are prescribed to which populations of veterans is useful in guiding the care of veterans. For example, it is hypothesized that older AEDs are still being used by older veterans, who may have been taking these AEDs for years.”
To test that hypothesis, researchers collected demographic characteristics, including age and gender, for VHA patients with a seizure diagnosis, seizure on their problem list and who were prescribed an AED for at least 30 days during FY11.
AEDs were divided between older (first generation) and newer, while veteran ages were grouped by decades — 20s, 30s, etc. The researchers then measured the frequencies of each AED within each age group and in total.
Results indicate that most veterans were prescribed either one (66%) or two (27%) AEDs during FY11. In addition, 43% of veterans were found to be taking only older AEDs, with 20% using both older and newer drugs.
The age groups with the highest percentages of use of only older AEDs were in their 60s (44%), 70s (51%) and 80s (53%). Most commonly prescribed were phenytoin (36%), levetiracetam (27%), gabapentin (20%) and valproate (15%), according to the report.
Another study presented late last year at the American Epilepsy Society Annual Meeting noted that the mean age of deceased epilepsy patients, 97% male, was 69.9% at the VA compared to 76.3 for males in the United States overall.2
That presentation, including some of the same authors as the recent study, also pointed out that an algorithm validated for identifying epilepsy in geriatric patients was not appropriate for making the diagnosis in the general VA population. One statistic spurring the study was that the number of veterans being treated for epilepsy at the VA decreased by 7,818 — from 68,909 to 61,091 from fiscal 2010 to fiscal 2011.
1 Tran T, Rehman R, Husan A. Prescribing Trends of Antiepileptic Drugs for Epilepsy within the Veterans Health Administration. Presented at the American Academy of Neurology 2014 Annual Meeting, April 30, 2014, Philadelphia.
2Rehman R, Everhart A, Figueroa-Garcia A, Frontera A, Riley D, Schoof D, Lopez M. Validation of an Algorithm for the Identification of Epilepsy Patients in the Veterans Health Administration (VHA) (Abst. 2.273 ). American Epilepsy Society Annual Meeting. Dec. 5-9, 2013; Washington.