Which of the following is an antiepileptic drug?

• A. Diazepam
• B. Phenytoin
• C. Levetiracetam
• D. Prednisone

Answer: (B)

Antiepileptic drugs work by dampening abnormal brain excitability to prevent seizures. Phenytoin fits as a classic antiepileptic because it primarily blocks voltage-gated sodium channels in neurons. This action stabilizes the cell membrane and lowers the likelihood of rapid, repetitive firing that sustains seizures, making it effective for long-term maintenance in many seizure types. While diazepam also has anticonvulsant properties and can stop seizures acutely, it is not typically used as a steady maintenance drug due to tolerance and dependence. Levetiracetam is indeed an antiepileptic with broad use, but the traditional, textbook example among these options for ongoing seizure control is phenytoin. Prednisone is a corticosteroid and not an antiseizure medication.