Abstract: 　Objective To study the clinical features ,diagnosis and treatment of phenytoin (PHT) toxicity in both epileptic and non-epileptic patients, a brief review of PHT toxicity also made. Method Retrospective study of 14 cases of acute PHT toxicity admitted to our hospital from 1988 to 2008,analysis were made of their clinical feature, cause of toxicity ,medication of antiepileptic drugs, blood concentration of PHT and prognosis. Results Cerebellar syndrome is the cardinal clinical feature, some of them manifest the extra-pyramidal syndrome in both epileptic and non-epileptic patients. History of taking antiepileptic drugs is straightforward and immediate diagnosis and treatment can be done timely in epileptic patients; in contrast, ambiguity of medications history made the diagnosis and treatment delay and wasting unnecessary examinations in non-epileptic patients. All 3 cases of non-epileptic patients are uninformed ingestion of PHT, in order to control symptoms of asthma they take anti-asthma compound with brand name “fei-bao”，which main component is PHT, their clinical presentation is episode ataxia. Prognosis of acute PHT toxicity is favorable. Conclusion First report of acute PHT toxicity in patients with asthma taking PHT compound. High index of suspicion of PHT toxicity should be raised whenever patients with unexplained cerebellar syndrome are encountered, no matter they are epileptic and non-epileptic. It is inadvisable to use PHT as fist line medication in treating non-epileptic disorders. A brief review discuss the pharmacokinetics of PHT susceptible to toxicity and the mechanism and risk factors of PHT toxicity.

Key words: PHT toxicity, uninformed ingestion of PHT, episode ataxia