Abstracts

Approximately 10% of nursing home residents are prescribed antiepileptic drugs (AEDs). In one cross-sectional study of nursing home residents, the primary factors associated with AED use were epilepsy/seizure, peripheral vascular disease and bipolar depression; however, the analysis determining the indication for AED treatment relied on multivariate analysis of International of Classification of Diseases, Ninth revision (ICD-9) coding and the minimum data set (MDS), rather than on direct chart abstraction. ICD-9 coding is often unreliable and MDS has been rarely used in studies of epilepsy or AED treatment. In this preliminary study, the indications for AED treatment were determined by direct review of the medical chart. In a population-based study of nursing homes in Northern Manhattan and Central Harlem, we used pharmacy databases to identify nursing home residents taking AEDs. Chart reviews were performed to identify the medications prescribed and the indications for AED treatment. If an AED was used to treat a convulsive disorder, an attempt was made to further classify the seizure diagnosis using International League Against Epilepsy (ILAE) guidelines. Of the 73 patients reviewed thus far, 54 (74%) patients were prescribed AEDs because of a history of seizures. Twenty-six patients (36%) met definite criteria for the diagnosis of epilepsy or single-unprovoked seizure. An additional 25 patients (34%) had a diagnosis of seizure disorder but could not be further classified. Three patients (4%) had acute symptomatic seizures or were being treated with AEDs for seizure prophylaxis. Nineteen (26%) patients who were receiving AEDs did not have a history of seizures. They were prescribed AEDs because of pain and/or psychiatric illness.
The most commonly prescribed AEDs were phenytoin (37/73 or 51%), gabapentin (18/73 or 25%) and valproic acid (14/73 or 19%). Thirteen out of 18 patients were prescribed gabapentin for pain and 10/14 patients were prescribed valproic acid for psychiatric reasons. All patients taking phenytoin were being treated for seizures or epilepsy. Fifteen patients (21%) were receiving two or more AEDs. Among nursing home residents, phenytoin continues to be the most prevalent AED prescribed for the treatment of seizures/epilepsy. The second and third most commonly prescribed AEDs, gabapentin and valproic acid, are largely being used for the treatment of pain and psychiatric reasons. (Supported by AAMC grant# MM0323)