This invention provides a pain relief agent (analgesic agent) for non-inflammatory pain disease, which contains as an effective ingredient an sialic acid or its pharmaceutically acceptable salt. The sialic acid, which is an effective ingredient of the medicine of this invention, exhibits excellent pain relieving (analgesic) activity on a diseased model animal suffering from neurogenic pain, which is a non-inflammatory pain. Therefore, the pain relief agent of this invention is useful for treating non-inflammatory pain caused by diseases such as trigeminal neuralgia, postzoster neuralgia, strangulated neuropathy, complex regional pain syndrome, diabetic neuropathy, neuropathy caused by trauma, phantom limb pain, central pain after spinal injury or post cerebral stroke, as well as neurophathics caused by a pharmacotherapy or a radiation therapy.本發明是關於針對非炎症性疼痛疾病的鎮痛劑,係含有唾液酸或其藥學上可容許之鹽作為有效成份。本發明有效成份之唾液酸,對於非炎症性疼痛的神經性疼痛的病理模型動物顯示鎮痛作用。因此,本發明鎮痛劑有用於作為用以治療,例如,三叉神經痛、帶狀疱疹後神經痛、包埋性神經病變、複合性局部痛症候群(CRPS)、糖尿病性神經病,外傷引起的神經障礙、幻肢痛、脊椎損傷後或腦中風後之中樞疼痛,以及藥物療法或放射線治療法所引起的神經病變等神經性疼痛疾病之非炎症性疼痛疾病之藥劑。
