Phenobarbital is a long-acting barbiturate used to treat generalized tonic-clonic seizures and fever-induced convulsions.

• A. To treat insomnia
• B. To treat generalized tonic-clonic seizures and fever-induced convulsions
• C. To treat anxiety
• D. To relieve pain

Answer: (B)

Phenobarbital’s primary clinical effect is its anticonvulsant action. It’s a long-acting barbiturate that enhances GABA-A receptor activity, increasing chloride influx and dampening neuronal excitability. This mechanism directly helps prevent seizure activity, making it a well-established treatment for generalized tonic-clonic seizures and fever-induced convulsions in children. While barbiturates can cause sedation and have historical uses for insomnia or anxiety, those are not the main indications today, and phenobarbital isn’t used for pain relief. The key idea is that its strongest and most appropriate use is controlling seizures, including febrile seizures.