Efficacy of phenobarbital in neonatal seizures.

A retrospective study of neonatal seizures in a tertiary care neonatal intensive care unit determined a 3.2% incidence, and confirmed the relatively poor efficacy of the traditional anticonvulsants phenobarbital and phenytoin. Only 33% responded to an initial adequate loading dose of phenobarbital, while 56% responded to either or both anticonvulsants. Although multifocal clonic seizures were most common (42%), tonic seizures were next in frequency (30%). Tonic seizures which did not respond to phenobarbital responded quite poorly to the addition of phenytoin compared to other seizures types. Tonic seizures may be the result of brainstem release phenomena and require a different strategy for management. Among nonresponders in this study, there was a 56% mortality rate but only 33% of responders died. There is a critical need for studies to find more efficacious agents than phenobarbital and phenytoin to treat seizures in the newborn.