Seizures in patients with glioma treated with phenytoin and levetiracetam

Abstract

e13020 Background: Seizures are common in patients with glioma. Phenytoin, traditionally used for these patients, can be associated with intolerable side effects and potentially alters the metabolism of chemotherapeutic agents. Levetiracetam has more favorable pharmacokinetics facilitating ease of use with fewer side effects and is nonenzyme inducing. We compare seizure outcomes and side effects in patients with glioma treated with phenytoin and levetiracetam monotherapy. Methods: Retrospective analysis of consecutive patients with glioma. Subjects had at least one clinical seizure and had to be followed for 6 months. Seizure outcomes and side effects were compared between cohorts treated with phenytoin or levetiracetam. Seizure outcomes were measured by time to second seizure and seizure frequency. Results: 76 patients (34 female) with pathologically proven glioma and seizures were identified, 25 treated with phenytoin and 51 with levetiracetam. 64% had grade 4 astrocytoma. There was no difference in seizure outcome between the phenytoin and levetiracetam groups when comparing time to second seizure (p = 0.584), second seizure rates (p = 0.462), and average seizures per month (p = 0.776). When adjusting for age, gender, type of seizure, type of glioma, and dosage using univariate and multivariate models there were no differences between the treatment groups and none of these covariates were statistically significant for explaining the second seizure rates between treatment groups (all p values >0.05). The incidence of side effects in the levetiracetam group was 5.9% versus 20% in the phenytoin group (p = 0.106). Additionally, 36.0% of the patients in the phenytoin group had dose adjustments not related to breakthrough seizures compared to only 9.8% in the levetiracetam group (p = 0.010). Conclusions: In this study, glioma patients treated with levetiracetam had similar seizure control as patients treated with phenytoin. Patients treated with levetiracetam experienced fewer side effects and required fewer non seizure related dose adjustments than patients treated with phenytoin. Levetiracetam is a safe, effective, and preferred alternative for seizure management in patients with glioma. No significant financial relationships to disclose.