No evidence for antiepileptic drugs preventing seizures in people with brain tumours

Clinical question: 
How effective and safe are antiepileptics in preventing seizures in people with brain tumours?
Bottom line: 
Compared to placebo or no treatment, the antiepileptic drugs phenytoin, phenobarbital and divalproex sodium, were no more effective or were less effective in preventing a first seizure in 404 people with brain tumours.
Caveat: 
The risk of adverse effects, such as nausea, skin rash, sore gums, myelosuppression, vertigo, blurred vision, tremor and gait unsteadiness was higher for those taking antiepileptic drugs (NNH* 3). No studies were identified evaluating use of newer antiepileptic drugs. Antiepileptic drugs can also interact with chemotherapy agents and steroids. NNH = number needed to treat to cause harm in one individual.
Context: 
Up to 60% of people with brain tumours may present with seizures, or may have a seizure for the first time after diagnosis or neurosurgery. The risk of seizures varies with the tumour type and tumour location in the brain. Seizures have a negative impact on quality of life, affecting activities of daily living, independence, work and driving.
Review CD#: 
CD004424
PEARLS No: 
84
Date: 
August, 2008
Authored by: 
Brian R McAvoy