A cost-minimization analysis of phenytoin versus levetiracetam for early seizure pharmacoprophylaxis after traumatic brain injury

Background: Recent data indicate comparable efficacy and safety for levetiracetam (LEV) when compared with phenytoin (PHT) for prophylaxis of early seizures after traumatic brain injury. The purpose of this study was to conduct a cost-minimization analysis, from the perspective of both the acute care institution (cost) and patient (charges), comparing these two strategies. Methods: A decision tree was constructed to include baseline event probabilities obtained from detailed literature review, costs, and charges. Monte Carlo simulation was used to derive the mean costs and charges per patient treated with the LEV when compared with the PHT strategy. Adverse event probabilities, costs, charges, and frequency of laboratory determination for the PHT group were varied in sensitivity analyses. Results: Literature review indicated equal efficacy of PHT versus LEV for early seizure prevention. The PHT strategy was superior to the LEV strategy from both the institutional (mean cost per patient $151.24 vs. $411.85, respectively) and patient (mean charge per patient $2,302.58 vs. $3,498.40, respectively) perspectives. Varying both baseline adverse event probabilities and frequency of laboratory testing did not alter the superiority of the PHT strategy. LEV replaced PHT as the dominant strategy only when the cost/charge of treating mental status deterioration was increased markedly above baseline. Conclusions: From both institutional and patient perspectives, PHT is less expensive than LEV for routine pharmacoprophylaxis of early seizures among traumatic brain injury patients. Pending compelling efficacy data, LEV should not replace PHT as a first-line agent for this indication. Level of Evidence: II.