Which drug is a barbiturate used as an antiseizure medication?

Which drug is a barbiturate used as an antiseizure medication?

• A. Phenytoin
• B. Phenobarbital
• C. Valproic acid
• D. Gabapentin

Answer: (B)

Barbiturates enhance GABA's inhibitory effect at GABA-A receptors, increasing chloride influx and making neurons less excitable—this is why they can prevent seizures. Among the options, the barbiturate used as an antiseizure medication is phenobarbital. It has a long duration of action and has been a mainstay for various seizure types, including in neonates and certain refractory cases. The other drugs are not barbiturates: phenytoin is a Na+ channel blocker (hydantoin); valproic acid has broad mechanisms including increasing GABA and affecting Na+/Ca2+ channels; gabapentin is a GABA analog that modulates calcium channels.

Barbiturates enhance GABA's inhibitory effect at GABA-A receptors, increasing chloride influx and making neurons less excitable—this is why they can prevent seizures. Among the options, the barbiturate used as an antiseizure medication is phenobarbital. It has a long duration of action and has been a mainstay for various seizure types, including in neonates and certain refractory cases. The other drugs are not barbiturates: phenytoin is a Na+ channel blocker (hydantoin); valproic acid has broad mechanisms including increasing GABA and affecting Na+/Ca2+ channels; gabapentin is a GABA analog that modulates calcium channels.