A Review of the Use of Antiepileptic Drugs in High-Grade Central Nervous System Tumors

Background: Seizures are a common complication in patients with central nervous system (CNS) tumors. Optimal management is unclear with no defined guidelines and pharmacological management poses many controversies. Due to a hypothesized lack of consistency, we aimed to retrospectively review seizure management in patients with high-grade CNS tumors in our institution. Methods: The medical records of patients with high-grade CNS tumors referred to the specialist palliative medicine service in our institution from January-June 2008 were retrospectively reviewed. Seizure incidence, antiepileptic drug (AED) choice, neurology input, medication interactions, and appropriate drug level monitoring were assessed. Results: Twenty-seven patients were included for analysis. Fifteen (56%) were female. The mean age was 58.8 years (range 31-82 years). Three (11%) patients presented with seizures and 8 (30%) developed seizures subsequently. Eight (73% of those with seizures) were on monotherapy AED. Six different agents were used as first-line agents. Phenytoin was the most common AED used (n = 4). Three (27%) patients were on combination AEDs. Five (45.5%) patients had been seen by neurology and 6 (54.5%) had appropriate drug level monitoring performed. Six (55%) patients had potential AED-non-AED interactions. None of the patients had instructions documented in the clinical notes against driving. Conclusion: Seizure management in patients with CNS tumors is not consistent and remains very much a neglected area. Appropriate choice of AED is crucial. Physicians should be aware of potential drug interactions. Ownership and regular follow-up of this group is required to ensure optimum patient management.