Which of the following is an antiepileptic drug?

• A. Amoxicillin
• B. Metformin
• C. Simvastatin
• D. Carbamazepine

Answer: (D)

Antiepileptic drugs work by dampening abnormal electrical activity in the brain to prevent seizures. Carbamazepine does this by blocking voltage-gated sodium channels, which stabilizes neuronal membranes in the inactivated state and reduces high-frequency firing. This mechanism directly lowers the likelihood of the chaotic neuronal bursts that cause seizures, making it a classic antiepileptic choice for various seizure types. The other options are not antiepileptics: amoxicillin is an antibiotic, metformin is a antidiabetic medication, and simvastatin is a statin used to lower cholesterol.