Abstracts

Rationale: Levetiracetam (LVT) is a second-generation antiepileptic drug (AED) that has been marketed in the U.S. since 1999. In the initial stage, LVT use was restricted to adjunctive therapy for focal seizures, but a recent clinical trial demonstrated the effectiveness of LVT to treat various types of seizures. While LVT has come into general use, there are only a few case reports linking it to seizure aggravation. To date, no studies have provided information regarding the prevalence and risk factors of seizure aggravation caused by LVT. Methods: We retrospectively identified 125 children (0.3-18 years) with epilepsy who were newly treated with adjunctive levetiracetam therapy from November 2008 to July 2014 in Pusan National University Hospital. Forty-four patients were not enrolled based on the exclusion criteria. Aggravation was diagnosed if seizure frequency increased by more than 50% of baseline or there were new types of seizures after 1 month of adjunctive levetiracetam therapy. Results: Eighty-one patients (male:female, 44:37) were enrolled, including 27 (33.5%) with generalized seizures and 54 (66.7%) with focal seizures. Twelve patients (14.8%) exhibited seizure aggravation (group A) and 69 patients (85.2%) had improvement or no change after 1 month of adjunctive levetiracetam therapy (group B). Eleven patients (91.7%) in group A and 16 patients (23.2%) in group B had generalized seizures, with aggravation significantly more frequent in patients with generalized seizures (p < 0.001). Other factors such as age at diagnosis, age at adding levetiracetam, sex, baseline seizure frequency, etiology, electroencephalography and magnetic resonance imaging abnormalities, and concomitant drug use were not identified as risk factors. Conclusions: Adjunctive levetiracetam therapy was associated with worsened seizures in 14.8 % of included patients, especially those with generalized seizures. Careful monitoring for increased seizure frequency or the onset of a new type of seizures is advised for patients prescribed levetiracetam add-on treatment for the treatment of generalized seizures. Funding: This study was supported by the Pusan National University Hospital (2015 research grant).