Ryan T. Merrell, S. Keith Anderson, Fredric B. Meyer and Daniel H. Lachance
Second-generation antiepileptic drugs (AEDs) are increasingly used in the care of patients with glioma. There is little data on how this practice compares with the use of traditional AEDs in this population. This noninferiority analysis compares seizure outcomes and side effects in patients with glioma treated with phenytoin and levetiracetam monotherapy.
The authors retrospectively reviewed the records of 500 consecutive patients with glioma who were treated in clinical trials from 2001 to 2008 at 3 Mayo Clinic campuses. To be eligible for the study, these patients had to have had at least 1 clinical seizure and to have undergone follow-up for at least 6 months. Seizure outcomes, defined by the occurrence of a second seizure, time to second seizure, and seizure frequency, along with AED side effects, were compared between cohorts treated with phenytoin or levetiracetam
Seventy-six patients were identified, 25 treated with phenytoin and 51 with levetiracetam. Sixty-four percent of the patients had a 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 = 0.561), and average seizures per month (p = 0.776). When adjusting for age, sex, 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 6% versus 20% in the phenytoin group (p = 0.106). Additionally, 36% of the patients in the phenytoin group had dose adjustments unrelated to breakthrough seizures compared with only 10% in the levetiracetam group (p = 0.010)
In this study, patients with glioma treated with levetiracetam and phenytoin had similar seizure control. Patients treated with levetiracetam experienced fewer side effects and required fewer nonseizure-related dose adjustments than patients treated with phenytoin. Levetiracetam is a safe, effective, and preferred alternative for seizure management in patients with glioma.