Main Research Findings

Vigabatrin is an antiepileptic drug approved for the treatment of refractory partial epilepsy. 1 , 2 . While initial randomized controlled trials did not detect any major side effects associated with vigabatrin, longer-term observational studies have revealed that its use is linked to asymptomatic visual field constriction. 1 , 2 .

Vigabatrin has also been studied as adjunctive therapy for children with intractable epilepsy. 21 . The study found that vigabatrin was effective in children with intractable epilepsy.

Vigabatrin has been shown to be effective for the treatment of West syndrome. 6 , 27 . West syndrome is an epileptic syndrome that occurs in infancy, characterized by spasms, psychomotor retardation, and an EEG abnormality called hypsarrhythmia. 27 . West syndrome is often resistant to conventional antiepileptic drugs, and vigabatrin is considered a viable treatment option. 6 , 27 . Vigabatrin has shown effectiveness in treating West syndrome alongside valproic acid, benzodiazepines, adrenocorticotropic hormone (ACTH), and corticosteroids. 6 .

Vigabatrin has shown potential as a treatment for epileptic spasms and tonic seizures associated with tuberous sclerosis complex in children beyond infancy. 29 , 17 . Tuberous sclerosis complex is a genetic disorder that causes tumors to develop in various organs, including the brain. 29 . Vigabatrin is recommended as first-line therapy for infantile spasms in tuberous sclerosis complex. 17 .

Vigabatrin has also been found to be effective for children with refractory epilepsy. 7 . Vigabatrin decreased seizure frequency by at least 50% in 33.3% of patients with partial seizures and 30.6% of patients with primary generalized seizures. 7 . Moreover, six of the responders with partial seizures experienced complete resolution of their seizures. 7 .

Vigabatrin has been recommended as a first-line treatment for infantile spasms in many countries, replacing steroids. 10 . However, vigabatrin might not be more effective than steroids, especially corticotropin, particularly in children with tuberous sclerosis. 10 . Due to potential side effects like vision problems, ACTH is recommended as the first-line treatment for West syndrome. 10 .

There is evidence suggesting that vigabatrin might be as effective as ACTH for treating West syndrome. 15 . A randomized, prospective study comparing the effectiveness and relapse rates of ACTH and vigabatrin treatment showed no significant difference. 15 . Both drugs have serious side effects. Further research is needed to determine which drug is more effective. 15 .

Vigabatrin has been compared to carbamazepine as a new antiepileptic drug. 13 . There was no significant difference in effectiveness between vigabatrin and carbamazepine for monotherapy in children with newly diagnosed partial seizures. 13 . The side effects of both drugs were comparable. 13 .

Reasons for Side Effects

The side effects of vigabatrin are believed to stem from its inhibition of GABA (γ-aminobutyric acid) breakdown in the brain. 3 . GABA is an inhibitory neurotransmitter in the brain, responsible for suppressing nerve cell activity. 3 . When vigabatrin inhibits GABA breakdown, the concentration of GABA in the brain increases, which is thought to lead to side effects such as vision problems. 3 .

Common Side Effects

Vision Problems

Vigabatrin can cause vision problems. 1 , 2 , 9 , 6 , 28 , 5 , 22 , 24 . Asymptomatic visual field constriction is the most common vision problem associated with vigabatrin. However, symptoms such as reduced vision and visual field defects can also occur. 1 , 2 , 9 , 6 , 28 , 5 , 22 . Vision problems caused by vigabatrin can develop weeks to years after starting the medication. 1 , 2 , 9 . While stopping vigabatrin can improve vision problems, complete recovery is not guaranteed. 9 , 6 .

Weight Gain

Vigabatrin can cause side effects such as increased appetite and weight gain. 7 , 16 . Weight gain from vigabatrin is thought to be related to its effect on raising GABA levels in the brain. 16 . Since GABA plays a role in suppressing appetite, increasing its levels with vigabatrin could lead to increased appetite and subsequent weight gain. 16 .

Rash

Vigabatrin can trigger skin reactions, including rashes. 17 .

Behavioral Changes

Vigabatrin may cause behavioral changes as a side effect. 17 .

Side Effect Management

Vision Problems

It's recommended to undergo an eye exam before starting vigabatrin treatment. 5 . Regular eye exams during treatment are essential. 5 . If vision problems are detected, discontinuing vigabatrin may be necessary. 9 , 6 .

Weight Gain

Dietary and exercise interventions are recommended while taking vigabatrin. 16 . If weight gain associated with vigabatrin is a concern, consulting with a doctor is crucial. 16 .

Study Comparisons

Commonalities

Multiple studies have indicated that vigabatrin is effective for treating refractory epilepsy. 1 , 21 , 7 , 2 .

Differences

Certain studies have shown variations in the effectiveness and side effects of vigabatrin. 10 , 15 . For instance, vigabatrin might not always be more effective than steroids. 10 . While vigabatrin can cause side effects like vision problems, some studies suggest a lower risk of visual field defects associated with the drug. 6 .

Practical Implications

Vigabatrin is a valuable medication for treating refractory epilepsy, but it has the potential to cause vision problems and other side effects. 1 , 2 , 9 . When taking vigabatrin, it's vital to follow your doctor's instructions carefully and undergo regular eye exams. 5 . If you experience any symptoms such as vision problems, contact your doctor immediately. 9 .

Current Research Limitations

Research on the side effects of vigabatrin is still insufficient. 24 . Long-term effects of vigabatrin remain largely unknown. 24 .

Future Research Directions

Further research on the side effects of vigabatrin is necessary. 24 . Specifically, research needs to focus on the long-term effects of vigabatrin and methods to mitigate the risk of vision problems. 24 .

Conclusion

Vigabatrin is an effective medication for treating refractory epilepsy, but it can cause vision problems and other side effects. 1 , 2 , 9 . Always follow your doctor's instructions and get regular eye exams when taking vigabatrin. 5 . Further research is needed on the side effects of vigabatrin. 24 .