Abstracts

Rationale: Therapeutic drug monitoring (TDM) is routinely used for all antiepileptic drugs (AED) for patients with epilepsy. The purpose of this study was to assess the perceived importance of a TDM service for patients with refractory epilepsy at a referral center based on the patients’ opinion.Methods: An anonymous questionnaire was distributed to adult patients admitted to the National Center for Epilepsy during August 2014-May 2015 regarding the patients’ view of use of AEDs and how they regarded the TDM service as a part of their treatment. In addition, patient interviews were performed on the same topic. The Local Ethics Committee approved the study.Results: In total, 211 patients were included (127 women/84 men); average age 36 years (range 17-78), age at onset of epilepsy 19 years (0-78), mean number of AEDs in use 1.8 (1-4), other drugs 1.1 (0-12), 65% used polytherapy of AEDs. 24 different AEDs were used; lamotrigine, valproate and levetiracetam were the top 3, accounting for 54% of the users. 82% (n=198) of the patients appreciated the use of TDM as important. 54% reported that TDM was performed twice a year or more frequently, 30% once a year and 16 less than once a year. The interviews elucidated the appreciation of feeling well taken care of, fear of adverse effects and a quality assurance of the treatment.Conclusions: The present results demonstrate that the great majority of patients with refractory epilepsy and an extensive polypharmacy burden appreciate the TDM service; that regular serum drug concentration measurements are performed. They feel well cared for and are concerned about possible adverse effects related to high concentrations. This underlines the need for a close monitoring of AEDs as an important part of patient safety and comprehensive care.