Vigabatrin acts by

Mechanism of Action: Vigabatrin is an irreversible inhibitor of GABA aminotransferase (GABA-T), the enzyme responsible for the degradation of GABA. It may also inhibit the vesicular GABA transpoer. Vigabatrin produces a sustained increase in the extracellular concentration of GABA in the brain. This leads to some desensitization of synaptic GABA A receptors but prolonged activation of nonsynaptic GABA A receptors that provide tonic inhibition. A decrease in brain glutamine synthetase activity is probably secondary to the increased GABA concentrations. Vigabatrin is useful in the treatment of paial seizures and infantile spasms Reference: Katzung Pharmacology; 13th edition; Chapter 24; Antiseizure drugs