Fosphenytoin in infants of extremely low birth weight.

Fosphenytoin, a phosphorylated prodrug of phenytoin, is useful for acute seizures, is given by parenteral administration, and has few cardiac and local irritation adverse effects. There is limited experience in the administration of this new agent to newborns, and concern has been raised regarding the conversion of the prodrug to phenytoin. In two low--birth-weight infants, it was observed that fosphenytoin was converted adequately with varying effects on seizure control.