Clinical Use and Efficacy of Levetiracetam for Absence Epilepsies

Background: Levetiracetam is prescribed for a broad spectrum of seizure types but does not have a specific indication for absence epilepsy. We hypothesized that levetiracetam is commonly prescribed for children with absence epilepsies and evaluated the efficacy of this medication for absence epilepsy treatment in clinical practice. We also hypothesized that electroencephalographic (EEG) findings could help predict levetiracetam efficacy. Methods: We reviewed the charts of all patients treated for new-onset absence epilepsies at our pediatric neurology clinic between January 2011 and January 2016. Among 158 children diagnosed with absence epilepsies, 72 were treated with levetiracetam. Results: Levetiracetam was discontinued in 74% (n = 53/72) because of incomplete seizure control (59%, n = 35/72) and/or intolerable side effects (41%, n = 24/72) after a median 8.5 months (interquartile range 2, 17 months). Among patients for whom levetiracetam was effective, 44% (n = 8/18) had polyspikes on their initial EEG, versus 27% (n = 14/52) of patients for whom levetiracetam was discontinued (P =.17). The maximal prescribed dose was lower for children in whom levetiracetam was effective (29 ± 13 mg/kg/d) than those for whom levetiracetam failed (42 ± 20 mg/kg/d; P =.005). Conclusion: In routine clinical practice, levetiracetam is often chosen for patients with absence seizures. However, only about one-quarter of children with absence epilepsy in this study became seizure free with levetiracetam. When effective, levetiracetam can control absence epilepsy at a relatively low dose. Lack of seizure control requiring continued dose escalation should prompt early consideration of a therapeutic medication transition.