retigabine

Retigabine, also known as ezogabine, is an anticonvulsant drug of the potassium channel opener class. It was developed to treat partial-onset seizures.

Mechanism: It acts as a positive allosteric modulator of neuronal voltage-gated KCNQ2-5 potassium channels, enhancing the M-type potassium current. This stabilizes the resting membrane potential and reduces neuronal excitability, helping to prevent seizure activity.

Medical use and regulatory status: Retigabine was approved by the U.S. Food and Drug Administration in 2011 as an adjunctive treatment for refractory partial-onset seizures, marketed in the United States under the brand name Potiga. In the European Union it was marketed as Trobalt. The drug later carried warnings for several safety concerns, including bluish skin discoloration, vision changes, and urinary retention. In 2017 it was voluntarily withdrawn from the market in multiple regions due to safety concerns and company considerations, and is no longer widely available in many markets.

Safety and adverse effects: Common adverse effects include dizziness, fatigue, confusion, bluish skin discoloration, urinary retention, and somnolence. Less common but notable events include retinal pigment changes and vision disturbances; patients may require periodic eye examinations while on therapy. As with other anticonvulsants, drug interactions and careful titration are important.