Diphenylhydantoin is a chemical compound that is commonly used as an anticonvulsant medication. This compound is also known by the brand name Dilantin. There are several synonyms for this compound, including phenytoin, Phenytek, Epanutin, and Dilantin Infatabs. These synonyms are often used interchangeably to refer to diphenylhydantoin in medical circles. While diphenylhydantoin is most commonly used to treat epilepsy, it can also be used to treat other conditions such as trigeminal neuralgia and arrhythmia. The various synonyms for diphenylhydantoin make it easier for medical professionals and patients to communicate about this important medication.