17.4 : 抗癫痫药物：GABA 能通路增效剂

γ-aminobutyric acid or GABA pathway potentiators are drugs used to manage epilepsy by enhancing GABA neurotransmission, a critical inhibitory pathway in the brain.

Some commonly prescribed GABA potentiators include benzodiazepines, tiagabine, and sodium valproate. Each of these drugs differs slightly in its mechanism of action.

Benzodiazepines, like clorazepate, act on GABA_A receptors, enhancing its affinity for GABA. This opens the channel and amplifies GABA's inhibitory effects on neuronal excitability, raising the seizure threshold.

Tiagabine inhibits the GABA transporter GAT-1, prolonging GABA's presence in the synaptic cleft and inhibiting seizures.

Sodium valproate increases the GABA concentration in the brain, reducing seizure activity.

Clorazepate and sodium valproate effectively treat absence seizures, while tiagabine treats focal seizures.

When administered orally, these drugs are well absorbed. They are metabolized in the liver and excreted in urine.

Potential side effects include drowsiness, dizziness, gastrointestinal disturbances, ataxia, and tremors.