Acute psychosis due to treatment with phenytoin in a nonepileptic patient.

The development of psychosis related to antiepileptic drug treatment is usually attributed to the interaction between the epileptic brain substratum and the antiepileptic drugs. The case of a nonepileptic patient who developed psychosis following phenytoin treatment for trigeminal neuralgia is described. This case suggests that the psychotic symptoms that occur following phenytoin treatment in some epileptic patients may be the direct result of medication, unrelated to seizures.