Safety profile of two novel antiepileptic agents approved for the treatment of refractory partial seizures: Ezogabine (retigabine) and perampanel

Introduction: Complex-partial seizures are frequently resistant to antiepileptic therapy. Two new medications with mechanisms of action novel within the antiepileptic class have recently received approval for the adjunctive treatment of partial (focal) seizures. Areas covered: A Medline search was conducted to identify preclinical and clinical studies of ezogabine and perampanel. This was supplemented with additional articles obtained from online sources and information provided by the FDA and the manufacturers. The focus of this review is on the safety profiles of ezogabine (retigabine), a novel antiepileptic that targets voltage-gated potassium channels, and perampanel, a noncompetitive α-amino-3-hydroxyl-5-methyl-4-isoxazole- propionate glutamate receptor antagonist. Expert opinion: Central nervous system effects are predominant within the adverse event profiles of both ezogabine and perampanel. In addition, ezogabine exerts its inhibitory effects on potassium channels in the urogenital tract potentially resulting in urinary retention and related outcomes. Recent reports of blue discoloration of the skin and in the retinas of long-term ezogabine users have surfaced. Both drugs have demonstrated the ability to induce neuropsychiatric symptoms. Though both are welcome additions to the antiepileptic drug class, additional monitoring, appropriate counseling, and careful selection of patients are warranted to minimize adverse events.