A compound of formula:wherein A, Ar, R3, R6, and m are disclosed herein, or a pharmaceutically acceptable salt thereof (a “Cyanoiminopiperazine Compound”), compositions comprising an effective amount of a Cyanoiminopiperazine Compound, and methods for treating or preventing pain, urinary incontinence, an ulcer, inflammatory-bowel disease, irritable-bowel syndrome, an addictive disorder, Parkinson's disease, parkinsonism, anxiety, epilepsy, stroke, a seizure, a pruritic condition, psychosis, a cognitive disorder, a memory deficit, restricted brain function, Huntington's chorea, amyotrophic lateral sclerosis, dementia, retinopathy, a muscle spasm, a migraine, vomiting, dyskinesia or depression in an animal comprising administering to an animal in need thereof an effective amount of a Cyanoiminopiperazine Compound are disclosed.