The use of antiepileptic medication in a population-based cohort of adults with learning disability and epilepsy

Abstract

The purpose of the current study was to assess the trend of antiepileptic drug use in a sample of 143 adults with learning disability and epilepsy in one health district. Information on the dose and serum level of antiepileptic drugs received by the subjects, their demographic data and the epilepsy-related data were gathered from the medical case-notes, examination of subjects and interview with the carers. Sixty (42% of the cohort) subjects received polytherapy of antiepileptic medication. The use of polytherapy was significantly associated with being female, longer duration of epilepsy, multiple-seizure type, and active epilepsy (i.e. seizure during the previous 12-month period). Of the cohort, 52% receivd sodium valproate, 38.5% received carbamazepine, 29% phenytoin, 11% lamotrigine and 11% primidone. The majority of subjects received antiepileptic drugs within the BNF-recommended range; however, 38% of the subjects receiving carbamazepine had a lower dose than that recommended in the BNF. The serum levels of most antiepileptic drugs were within the local laboratory reference range, except that in 39% of cases the phenytoin level was below the local reference range. No statistically significant difference was observed in the use of different antiepileptic drugs and the rate of mental disorder in the cohort, although the subjects receiving lamotrigine and primidone showed more behavioural problems. Similarly, no significant association was observed between the seizure types and the use of different antiepileptic medications.