Choosing an antiepileptic. Selecting drugs for older patients with epilepsy

After age 65, the incidence of epilepsy increases rapidly. Approximately 1.5% of Medicare recipients and 10% of nursing home residents are being treated with antiepileptic drugs (AEDs). The most commonly used AED is phenytoin, a first generation agent. Appropriate drug selection in this population is complicated by the fact that multiple comorbidity is commonplace. Most older patients receive a number of drugs in addition to AEDs. The average nursing home patient receives six additional medications. Age-related issues affecting the choice of an AED include changes in protein binding, decreases in hepatic and renal clearance, and alterations in gastrointestinal absorption. AEDs that do not have drug-drug interactions, are not metabolized by the liver, and are readily absorbed may be better suited for the elderly. This paper reviews the present knowledge base and attempts to develop a more rational approach to AED selection for the elderly.