Medicine & USMLE


  1. Valproic Acid (Valproate)
  2. Carbamazepine
  3. Ethosuximide
  4. Gabapentin
  5. Lamotrigine
  6. Levetiracetam
  7. Barbituates (Phenobarbital, Thiopental)
  8. Topiramate
  9. Vigabatrin


Vigabatrin is an antiepileptic drug that functions by increasing the availability of GABA in the brain. GABA is an inhibitory neurotransmitter that suppresses the generation and propagation of action potentials or neural impulses in the brain, which are responsible for seizures.  Vigabatrin  is a narrow spectrum antiepileptic, meaning that it is mainly used for treating focal or partial seizures. A major side effect to watch out for with vigabatrin is permanent vision loss.

Key Points

  • Vigabatrin
    • Mechanism
      • Increases GABA concentration
        • Inhibits GABA transaminase, which blocks the breakdown of GABA
        • GABA is an inhibitory neurotransmitter; more GABA causes CNS depression and inhibition of neuronal impulses
    • Clinical Use
      • Partial (focal) seizures
        • Narrow-spectrum antiepileptic
    • Adverse Effects
      • Permanent visual loss
        • black box warning