Fosphenytoin

**Semantic type:** Pharmacologic Substance

**Definition:** A water-soluble phosphate ester prodrug of phenytoin, a hydantoin derivative with anticonvulsant activity. Fosphenytoin is hydrolyzed to phenytoin by phosphatases. Phenytoin exerts its effect mainly by promoting sodium efflux and stabilizes neuronal membranes in the motor cortex. This leads to a suppression of excessive neuronal firing and limits the spread of seizure activity.

**Synonyms:** - FOSPHENYTOIN