Abstracts

Rationale: In patients taking antiepileptic drugs (AED) for epilepsy, adverse effects (AE) often lead to low quality of life, impaired adherence, and eventually discontinuation of pharmacological treatment. This study aimed to identify independent predictors including AED administered in mono- or duotherapy for overall high AE burden and for specific AE.Methods: In our epilepsy outpatient clinic, all patients aged 16 years or older with epilepsy lasting for 12 months or more were routinely asked to complete the Liverpool Adverse Event Profile (LAEP; 19 items; score 19-76). Demographic, epilepsy and treatment variables were derived from our comprehensive outpatient database and entered into logistic regression analyses. Patients treated with the most frequent AED mono- or duotherapy regimen (> 5% of patients, resp.) were included.Results: Out of 841 patients included, 466 (59.4% female; mean age 44.4±17.1 years) were on monotherapy either with levetiracetam (n=151), lamotrigine (n=167), valproic acid (n=73), or carboxamide derivates (n=75). Independent predictors for high AE burden (LAEP score ≥45) were duration of epilepsy (OR 1.02), lack of terminal 12-month seizure freedom (OR 2.39), partial epilepsy (OR 2.83), but none of the four individual AED. Overall, the three most frequent AE were sleepiness (48%), difficulty concentrating (42%), and memory problems (39%). LAEP-defined AE were often independently predicted by lack of 12-month seizure freedom (10/19 AE) and female sex (7/19 AE). Furthermore, levetiracetam was significantly associated with depression (OR 3.00) and sleep disturbances (OR 2.36), lamotrigine with concentration difficulties (OR 2.59), valproic acid with shaky hands (OR 2.98), and carboxamide derivates with memory problems (OR 2.52). Two hundred thirty-nine patients (46.0% female; mean age 46.9±15.6 years) were on AED duotherapy with either lamotrigine–levetiracetam (n=45), carboxamide derivates–levetiracetam (n=26), lamotrigine–valproic acid (n=23), levetiracetam–valproic acid (n=18), or lacosamide–levetiracetam (n=14). In contrast to monotherapy, we did not find any independent predictor for high AE burden. Sleepiness was the most frequent AE (65%), followed by memory problems (49%) and difficulty concentrating (48%). LAEP-defined specific AE were mainly predicted by duration of epilepsy (5/19 AE) and lack of 12-month seizure freedom and drug resistance (3/19 AE, resp.). Duotherapy with levetiracetam–valproic acid was significantly associated with memory problems (OR 30.04) and nervousness (OR 10.82), lamotrigine–valproic acid with restlessness (OR 7.25), and lamotrigine-levetiracetam (OR 1.1) and lamotrigine–valproic acid with memory problems (OR 7.76).Conclusions: AED in individual mono- and duotherapies independently predicted some specific frequent AE, but not overall high AE burden. We conclude that our findings may help to identify patients with epilepsy and common AED in mono- or duotherapies who are at high risk for specific AE. In these patients, significant AED dose reduction, if possible, or change to other AED may reduce LAEP score and potential non-adherence.