Evaluation of intramuscular fosphenytoin vs intravenous phenytoin loading in the ED.

A comparison of length of stay in an emergency department (ED) after loading patients at risk for seizures with either intravenous (IV) phenytoin or intramuscular (IM) fosphenytoin was studied. This was a retrospective observational cohort study that was conducted over a 24-month period in an academic teaching hospital (693 beds). Patients included were 18 years or older, discharged from the ED without hospital admission, and loaded with either IV phenytoin or IM fosphenytoin. The primary end point was the comparison of length of stay in the ED until discharge after loading. Characterization of seizure etiology, cardiac risk factors, and adverse drug events were also observed. A total of 51 patients were evaluated who received IV phenytoin compared with 59 for IM fosphenytoin. The median time-to-discharge difference between IV phenytoin vs IM fosphenytoin was 1:49 hours (95% confidence interval, 1:24-2:24 hours; P < .001). There was no statistical difference in cardiac risk factors and occurrence of adverse drug events between groups. This study found that patients were discharged from the ED earlier with the loading of IM fosphenytoin compared to IV phenytoin.