Use of antiepileptic drugs in the elderly population.

Medical records for 572 patients in two extended care facilities were reviewed to study seizure disorders and antiepileptic drug use. Seventy patients (12.2 percent) were receiving antiepileptic drugs. Of this group, 43 patients (61.4 percent) had a diagnosis of epilepsy or documented seizures, 2 were being treated for neuralgia, and 25 (35.7 percent) had no reason given for antiepileptic use. The most common cause was cerebrovascular accident (38.9 percent), and no associated etiology was found in 29.2 percent. Phenytoin was the most commonly used agent. Thirty-two (45.7 percent) were taking two or more antiepileptic drugs. Thirteen patients had had no serum concentration monitoring in the last year. Thirty-seven patients (52.9 percent) had had at least one serum concentration outside of the therapeutic range.