Clinical use of antiepileptic drugs at a referral centre for epilepsy

PURPOSE The National Centre for Epilepsy in Norway admits patients with refractory epilepsy from the whole country. The purpose of this study was to investigate how antiepileptic drugs (AEDs) are used at the centre and compare it with the total consumption in the country and international guidelines regarding clinical use of AEDs. MATERIAL AND METHODS A prevalence study was carried out from patient records from 264 patients (136 adults and 128 children). The use of AEDs, gender, polytherapy, common drug combinations, serum concentration measurements, concomitant medication and comorbid conditions were investigated. RESULTS Of the 15 AEDs in use, valproate, lamotrigine and levetiracetam were most frequently used. In the country at large, carbamazepine, valproate and lamotrigine were used the most. Valproate and lamotrigine occurred most frequently in combination. In adults, oxcarbazepine and topiramate were used more frequently in women than in men. Children used benzodiazepines three times as often as adults. Newer AEDs were mostly used for partial seizures, in accordance with international guidelines. Thirty-five percent of adults and 20% of children suffered from comorbid CNS-related conditions. The use of concomitant medication was widespread. Serum concentrations were in accordance to recommended therapeutic ranges. CONCLUSION The results demonstrate that newer AEDs were much more frequently used at the epilepsy centre than in the country as a whole. The use of polytherapy was common, and therapeutic drug monitoring was used for optimal individualized drug treatment. AEDs were used in accordance to international guidelines and recommendations, which can serve as a reference for other prescribers.