McCleane Gary J, Suzuki Rie, Dickenson Anthony H
Rampark Pain Centre, Lurgan, Northern Ireland, and the *Department of Pharmacology, University College, Gower Street, London.
Anesth Analg. 2003 Nov;97(5):1474-1478. doi: 10.1213/01.ANE.0000085640.69855.51.
Neurokinin-1-expressing neurones in lamina I to III of the spinal cord are intimately involved in the regulation of ascending and spino-bulbal pathways that regulate excitatory transmission. In experimental animals, ablation of these neurones reduces the responses to a variety of nociceptive stimuli. Furthermore, in animals, spinal application of the selective 5HT3 receptor antagonist ondansetron mimics these effects, indicating that 5HT3 receptors play a pronociceptive role and mediate descending excitatory controls that allow spinal neurones to fully code peripheral stimuli. In this study, we examined the potential analgesic effect of a single IV injection of ondansetron in humans with chronic neuropathic pain. Each consenting subject received a single IV injection of 8 mg ondansetron and placebo in varying order at least 1 wk apart with pain scores being recorded for the 48 h preceding and after each injection. Pain scores were significantly reduced 2 h after ondansetron injection (but at no other time point). This suggests that ondansetron can have an analgesic effect in neuropathic pain. Side effects were minor and infrequent.
The selective 5HT3 receptor antagonist ondansetron, currently used as an antiemetic, may also have analgesic properties. Side effects with a single IV injection are infrequent and usually mild.
脊髓I至III层中表达神经激肽-1的神经元密切参与调节上行和脊髓-延髓通路，这些通路调节兴奋性传递。在实验动物中，切除这些神经元会降低对多种伤害性刺激的反应。此外，在动物中，脊髓应用选择性5-羟色胺3（5HT3）受体拮抗剂昂丹司琼可模拟这些效应，表明5HT3受体发挥促伤害感受作用并介导下行兴奋性控制，使脊髓神经元能够完整编码外周刺激。在本研究中，我们检测了单次静脉注射昂丹司琼对慢性神经性疼痛患者的潜在镇痛作用。每位同意参与的受试者以不同顺序至少间隔1周接受单次静脉注射8 mg昂丹司琼和安慰剂，并在每次注射前和后的48小时记录疼痛评分。昂丹司琼注射后2小时疼痛评分显著降低（但在其他时间点未出现此情况）。这表明昂丹司琼对神经性疼痛可能具有镇痛作用。副作用轻微且不常见。
目前用作止吐药的选择性5HT3受体拮抗剂昂丹司琼可能也具有镇痛特性。单次静脉注射的副作用不常见且通常较轻。
