Zonisamide is an anticonvulsant drug that is primarily used to treat epilepsy. This drug belongs to a class of drugs known as sulfonamides. It is known to be effective in reducing seizures in people with different types of epilepsy. There are several synonyms for the word "zonisamide" that are commonly used in scientific literature and medical practice. These include Excegran, Zonegran, and PMS-Zonisamide. Excegran and Zonegran are the brand names of the drug in Japan and the United States, respectively. PMS-Zonisamide is an unbranded version of the drug that is marketed in Canada. Overall, zonisamide is a widely used antiepileptic drug that has proven to be effective in the management of epilepsy.