ALISO VIEJO, Calif.--(BUSINESS WIRE)--Valeant Pharmaceuticals International (NYSE:VRX) announced today that it will initiate a clinical trial with retigabine in the treatment of pain associated with post-herpetic neuralgia (PHN). Valeant filed an Investigational New Drug (IND) application with the U.S. Food and Drug Administration (FDA) and following FDA review, the company will move forward with the clinical study. Retigabine is a first-in-class neuronal potassium channel opener currently in Phase 3 development as an adjunctive treatment for partial-onset seizures in patients with refractory epilepsy.