Ezogabine: A Novel Antiepileptic for Adjunctive Treatment of Partial-Onset Seizures

Epilepsy is defined as a tendency toward recurrent seizures unprovoked by any systemic or acute neurologic insults. It is a disruption of the electrical conductivity or activity in the brain, resulting in a seizure. In the United States, approximately 120 of every 100,000 people seek medical attention due to new seizure activity. Ezogabine, known as retigabine in Europe, is an ethyl N-(2-amino-4-[{fluorophenyl}methlamino]phenylcarbamate). The drug has been approved by the United States Food and Drug Administration (FDA) and European Medicines Agency for adjunctive treatment of partial-onset seizures in adults. Ezogabine exerts its therapeutic effect by enhancing transmembrane potassium channels (KCNQ ion channels), which is a novel mechanism in comparison with other antiepileptics. There are no specific documented contraindications to ezogabine. Warnings target patients that have benign prostatic hyperplasia or are receiving concomitant anticholinergic drugs due to a risk of urinary retention (2%). The FDA has required that ezogabine be part of a risk evaluation and mitigation strategy program in order to inform health care professionals of the risk of urinary retention. Prescribers should inform patients that ezogabine can cause urinary retention, including urinary hesitation, and instruct them to seek immediate medical attention if these symptoms occur. A medication guide has been developed for distribution to patients.