Evaluation of Levetiracetam Dosing Strategies for Seizure Prophylaxis Following Traumatic Brain Injury

Background: Although levetiracetam has been increasingly used as an alternative to phenytoin for early posttraumatic seizure prophylaxis following traumatic brain injury (TBI), an optimal dosing strategy has not been elucidated. The objective of this study is to determine whether different dosing strategies of levetiracetam are associated with the incidence of early posttraumatic seizures when used as prophylaxis following TBI.

Methods: This retrospective single-center cohort study included admitted patients ≥ 18 years of age with a diagnosis of TBI and receiving levetiracetam for early posttraumatic seizure prophylaxis between July 1, 2013, and September 1, 2019. The primary outcome of this study was to evaluate three different dosing strategies of levetiracetam (≤ 1000 mg/day, 1500 mg/day, and ≥ 2000 mg/day) and associated rates of early posttraumatic seizures. Secondary outcomes were to summarize absolute total daily maintenance doses of levetiracetam among patients who experienced early posttraumatic seizures compared with those who did not, to determine the impact of three different dosing strategies on hospital length of stay and in-hospital mortality, and to assess patient-specific variables on the occurrence of posttraumatic seizures. Overlap propensity score weighting was used to address the potential for confounding.

Results: Of the 1287 patients who received levetiracetam for early posttraumatic seizure prophylaxis during the study time frame, 866 patients met eligibility criteria and were included in the study cohort (289 patients in the ≤ 1000 mg/day group, 137 patients in the 1500 mg/day group, and 440 patients in the ≥ 2000 mg/day group). After weighting, the cumulative incidence of early posttraumatic seizure was 2.9% in the ≤ 1000 mg/day group, 8.8% in the 1500 mg/day group, and 9% in the ≥ 2000 mg/day group. The 1500 mg/day and ≥ 2000 mg/day levetiracetam groups had a 209% and 216% increase in the subdistribution hazard of early posttraumatic seizures compared with the ≤ 1000 mg/day levetiracetam group, respectively, but these differences were not statistically significant.

Conclusions: In conclusion, the results of this study demonstrate no statistically significant difference in the cumulative incidence of early posttraumatic seizures within 7 days of TBI between three different levetiracetam dosing strategies. After weighting, the ≤ 1000 mg/day levetiracetam group had the lowest rates of early posttraumatic seizures, death without seizure, and in-hospital mortality.