Vigabatrin in refractory complex partial seizures: The evidence of its therapeutic value

Vigabatrin (Sabril^®) has recently been granted approval in the Unites States for the adjunctive treatment of complex-partial seizures in adults. The drug was first evaluated as a potential therapy for this population decades ago, and it has been available in other parts of the world for some time. Well controlled studies demonstrate that at doses up to 3 g/day, the drug is efficacious as add-on therapy for treatment resistant seizures. However, vigabatrin has been associated with significant side-effects limiting its use, and relegating it to a late therapeutic alternative. Specifically, vigabatrin has been implicated in the development of irreversible peripheral vision loss in a significant number of patients. For this reason, the approval of the drug in the United States was contingent upon the introduction of a rigorous monitoring protocol that must accompany its use. Additionally, the drug has been associated with a relatively high incidence of psychiatric disturbances, although there is disagreement about a direct correlation of these symptoms to the drug. Still, the drug remains a viable alternative for patients who have failed therapy with traditional anti-seizure medications.