Neuropathic pain and fibromyalgia are intractable chronic pains. Neuropathic pain is defined as “pain caused by a lesion or disease of the somatosensory system” and is classified as peripheral or central neuropathic pain according to the site of the lesion or disease. The prevalence of neuropathic pain was estimated at 6.9% to 10% in some countries. Fibromyalgia is a disorder characterized by systemic pain accompanied by neuropsychiatric symptoms such as insomnia and depression and autonomic symptoms such as irritable bowel syndrome, gastroesophageal reflux disease, and over active bladder. In Japan, the prevalence was estimated to be 1.7%–2.1% and about 60%–80% of sufferers were women.