Abstracts

Rationale: With the marketing of a number of new antiepileptic drugs (AEDs) in recent years the pattern of prescription of AEDs has changed. The choice of optimal polytherapy poses difficulty for several reasons: there are limited data regarding favorable or unfavorable combinations and there is little systematic evidence that any two combinations are any more or less effective as any other. The clinician's choice of polytherapy is, in part, determined by his comfort with the AED chosen first for monotherapy. This may result in combinations of AEDs that are idiosyncratic for each practitioner, and not necessarily optimally selected for the patient requiring polytherapy. The aim of the present study was to examine the trends in the prescribing of AEDs, seizure frequency and self reported side effects in patients with drug resistant epilepsy at the tertiary referral center in Austria. Methods: 530 consecutive patients with epilepsy who where examined at the specialized epilepsy outpatient clinic of Department of Neurology, Medical University of Vienna, Austria, from June 2010 until October 2011 were enrolled in the study. Demographic data, current AEDs and seizure frequency were evaluated. All patients filled in the Hospital Anxiety and Depression Scale (HADS, German version) and a brief 19-item self-report instrument - the Adverse Events Profile (AEP), before attending clinician's office. Most common used AEDs and AED combinations were correlated with seizure frequency, most frequent reported side effects and anxiety and depression scores. Results: Monotherapy was used in 55,3% of patients, whereas 30,9% patients had 2 AEDs, 12,5% 3 AEDs and 1,3% of patients > 3 AEDs. 32,6% of patients were seizure free, 67,4% still had seizures. 32,3% of not-seizure-free patients had monotherapy, and the remaining patients had AED combination. The most frequent used drug was LVT in focal epilepsies (37%) and VPA in generalized epilepsies (44%). The most frequent used AEDs in patients with focal epilepsies who had monotherapy and were seizure-free were LVT (30%), CBZ (33%), and in patients with generalized epilepsies - LTG (29%) and VPA (50%). Most frequent reported side effects of AEDs were ataxia (p=0,048), aggression (p=0,014), nausea (p=0,052), cognitive impairment (p=0,059). Most common combination of AEDs were LVT+CBZ (25,3%), almost 31% of these patients were completely seizure free. The less common combinations were LVT+LTG (9,7%), LVT+LCS (9,3%) and LVT+OXC (8,0%). The patients who were seizure free had scored better in HADS (anxiety 8,9%, depression 5,8%) compared to patients who were not seizure-free (anxiety 16,6%, depression 12,5%). Conclusions: the present retrospective study provides updated information on the patterns of prescription of AEDs in al large population of patients with drug resistant epilepsies. The new AEDs were widely prescribed. There was a high portion of patients with more than one AED, which can be explained by increasing number of new AEDs, many of which are approved only for add on therapy.