Vigabatrin (Sabril®) is an antiepileptic drug (AED) that selectively
and irreversibly inhibits γ-aminobutyric acid (GABA) transaminase the enzyme responsible for the metabolism of the inhibitory neurotransmitter,
GABA – resulting in an increase in GABA within the central
nervous system. Although the exact mechanism by which vigabatrin
exerts its therapeutic effects is unknown, it is believed that the overall
increase in GABA inhibits the excitatory processes that lead to seizure
activity [1].
In 1989, vigabatrin was first approved in the UK as a second-line
treatment for uncontrolled complex partial seizures (CPS) and infantile
spasms (IS) [2]. Vigabatrin was well-tolerated during the course of
initial clinical studies [3–11]. Widespread availability in Europe led to
approximately 140,000 patients treated with vigabatrin from 1989 to
1997 [12].
An initial report from Eke et al. identified 3 adults treated with
vigabatrin who experienced symptomatic and persistent visual field
constriction [13]. Following additional reports in adults [13–15] and