A tolperisone-related compound or a compound of Formula Z is administered for the prevention and treatment of periodic paralyses and myotonias of several types, long QT syndrome, Brugada syndrome, malignant hyperthermia, myasthenia, epilepsy, ataxia, migraine, Alzheimer's Disease, Parkinson's Disease, schizophrenia, and hyperekplexia, neuropathic pain, and pain associated with nervous system disorders including, but not limited to, painful diabetic neuropathy, postherpetic neuralgia, trigeminal neuralgia, complex regional pain syndrome, Guillain-Barre syndrome (GBS), Charcot-Marie-Tooth (CMT) disease, complex regional pain syndrome, type 1 (CRPS-1), ischemic neuropathy, fibromyalgia, chronic fatigue syndrome, painful spasticities, and other nervous system disorders that have pain as an attendant sign and/or symptom.