Levetiracetam versus phenytoin: a comparison of efficacy of seizure prophylaxis and adverse event risk following acute or subacute subdural hematoma diagnosis.

BACKGROUND: Although both levetiracetam and phenytoin are used for seizure prophylaxis in subdural hematomas (SDHs), there is little data on their comparative efficacies. We compared the efficacy and risk of using levetiracetam versus phenytoin for seizure prophylaxis following acute or subacute SDH diagnosis.
METHODS: In this retrospective cohort study, the clinical data registry at a tertiary care hospital was searched for all cases of acute or subacute SDHs that were admitted to hospital in 2002, 2003, or 2011. Risk of clinical and/or electrographic seizures, and risk of adverse drug events were compared between the two exposure arms.
RESULTS: 124 subjects in the phenytoin arm and 164 subjects in the levetiracetam arm were included. There was no significant difference in clinical and/or electrographic seizure risk, though there was a decreased risk of adverse events in the levetiracetam arm (p < 0.001). In subjects with midline shift >0 mm, levetiracetam was associated with an increased risk of electrographic seizures during hospitalization (p = 0.028) and a decreased risk of adverse drug effects (p = 0.001), compared with phenytoin use.
CONCLUSIONS: Levetiracetam generally appears to have a similar efficacy to phenytoin in preventing clinical and/or electrographic seizures following acute/subacute SDH diagnosis, though patients with midline shift >0 mm may have associated with a higher risk of electrographic seizures on levetiracetam compared with patients on phenytoin. Levetiracetam is associated with a lower risk of adverse drug effects. A prospective, randomized study would more definitively determine any difference in efficacy and risk between phenytoin and levetiracetam.