Also known as: Dilantin®, Diphenylhydantoin, Phenytek®.

Because of phenytoin's potential adverse reactions (gingival hyperplasia, hirsutism, coarsening of facial features), other antiepileptic drugs are often prescribed for infants and young children. Phenytoin is commonly given with primidone, carbamazepine, phenobarbital, or valproate when monotherapy fails. It is ineffective in myoclonic, absence, and atonic seizures and is not recommended for the treatment of infantile spasms, Lennox-Gastaut syndrome, and epileptic syndromes in older children and adolescents when absence seizures or myoclonus is present. Intravenous phenytoin sodium is effective for status epilepticus and can be used as the initial drug to manage recurrent widely spaced seizures. This drug may also initially prevent seizures in high-risk patients with head trauma. Phenytoin has been advocated for many other disorders, however conclusive evidence of effectiveness is inadequate for most proposed indications.