Efficacy, Tolerability and Serum Phenytoin Levels after Intravenous Fosphenytoin Loading Dose in Children with Status Epilepticus

ABSTRACT

Objective: To evaluate the efficacy and tolerability of intravenousfosphenytoin in children with status epilepticus, and resultingserum total phenytoin levels.Methods: In this prospective study, 51 children aged less than 18years received intravenous loading dose of fosphenytoin (18-20mg/kg). Serum total phenytoin levels were estimated at 90 -100minutes. Outcomes studied were (i) seizure control and local and/or systemic adverse effects in next 24 hours and (ii) phenytoinlevels and its correlation with dose received, seizure control andadverse effects.Results: The actual dose of fosphenytoin received varied from15.1 to 25 mg/kg. Seizures were controlled in 45 (88%) childrenand, two required additional dose of 10 mg/kg. None of thechildren showed any local or systemic adverse effects. Serumtotal phenytoin levels were in the therapeutic range (10-20 μg/mL)in 12 (23.5%), sub-therapeutic in 16 (31.3%) and supra-therapeutic in 25 (49%) children. There was weak correlation ofthe phenytoin levels with dose of fosphenytoin received, seizurecontrol, or adverse effects.Conclusion: Intravenous fosphenytoin loading dose of 20 mg/kgis effective in controlling seizures in 88% of children with statusepilepticus, with a good safety profile. Seizure control and adverseeffects appear to be independent of serum total phenytoin levelsachieved.