Phenytoin versus fosphenytoin for second-line treatment of status epilepticus: propensity score matching analysis using a nationwide inpatient database.

PURPOSE

For status epilepticus, the choice of antiepileptic drugs for second-line treatment after benzodiazepine remains controversial: phenytoin or fosphenytoin are recommended, however, it has been unknown which is better. Using a nationwide database, we compared the efficacy and safety of them.

METHOD

An observational study conducted with the Japanese Diagnosis Procedure Combination inpatient database identified adult patients who had been admitted for status epilepticus and who had received intravenous diazepam on the day of admission from January 1, 2011 through December 31, 2015. Propensity score matching was applied to compare outcomes of the phenytoin and fosphenytoin groups.

RESULTS

The analysis examined data of 5265 patients: 2969 patients received phenytoin; 2296 received fosphenytoin, on the day of admission. One-to-one propensity score matching created 1871 matched pairs. No significant difference was found for vasopressor use on the day of admission (4.2 % vs. 4.4 %; odds ratio 1.07; 95 % confidence intervals 0.77-1.48; p = 0.69), or for mechanical ventilation on the day of admission, in-hospital mortality, length of hospital stay, or total hospitalization cost. Higher age, comorbidity of cardiac diseases and lower body mass index were associated significantly with increased vasopressor use, whereas the dose of phenytoin equivalents and the choice of fosphenytoin were not.

CONCLUSIONS

This nationwide observational study found no evidence that fosphenytoin provides higher efficacy or safety than phenytoin for treatment of status epilepticus in adults after diazepam. Age, cardiac disease and low body mass index were identified as independent risk factors for vasopressor use in both phenytoin and fosphenytoin.