This is a double-blind, randomized withdrawal study comparing CNV1014802 with placebo in patients with trigeminal neuralgia who have successfully responded to CNV1014802 in an initial open-label phase. Patients will participate in an initial open-label treatment period of 21 days of CNV1014802 150mg three times a day (tid). Responders will be randomized to 28 days of CNV1014802 150mg tid or placebo. Following an interim analysis after 10 evaluable patients have completed the open-label phase, the dose regimen may be increased to 350mg twice a day (bid) for the remainder of the trial if the responder rate is less than 60%.