Vigabatrin (VGB) is a novel
antiepileptic drug effective as adjunctive
therapy in patients with
partial seizures. In this study, the efficacy and tolerability of VGB as adjunctive
therapy were evaluated in patients with
refractory epilepsy. Adult patients with a definite diagnosis of
complex partial seizures and/or
partial seizures secondarily generalized were recruited from 10 Canadian centres. Patients were randomized to receive either active medication or placebo in a double- blind fashion and entered a 36-week titration and maintenance phase with regularly scheduled visits. Both efficacy parameters and safety assessments were monitored. Clinical laboratory, evoked potential studies, MRI, and neuropsychological tests were also performed. Forty-eight percent of VGB-treated patients vs. 26 percent of placebo-treated patients had a 50 percent or greater reduction in the frequency of
complex partial seizures and
partial seizures secondarily generalized.
Vigabatrin was well tolerated by the majority of patients. Minor neurological side effects were observed in a number of patients in both treatment groups. No serious systemic toxicity was observed. No changes in evoked potential studies or MRI findings were noted.
Vigabatrin was found to be an effective and well-tolerated
antiepileptic drug when used as adjunctive
therapy in patients with difficult to control
complex partial seizures and for
partial seizures secondarily generalized.
Vigabatrin is a selective irreversible inhibitor of the
GABA- degradating
enzyme GABA transaminase and has shown efficacy in a number of clinical trials in patients with difficult to control
partial seizures.
Vigabatrin has been found most effective against complex partial and secondarily
generalized tonic-clonic seizures in both adults and children.
Vigabatrin has also been shown to reduce
infantile spasms secondary to various aetiologies and is most effective in
spasms associated with
tuberous sclerosis. The aim of this study was to further extend the clinical experience with VGB as adjunctive
therapy in the treatment of adult patients with difficult to control
complex partial seizures and/or
partial seizures secondarily generalized. In addition to the assessments of efficacy and tolerability to VGB, neuropsychological evaluations were also carried out.