University Department of Anaesthesiology and Pain Therapy, Bern University Hospital, Inselspital, Bern 3010, Switzerland Department of Financial and Management Studies, School of Oriental and African Studies, University of London, London, UK Department of Economics and Institutions, University of Rome Tor Vergata, Rome, Italy Center for Sensory-Motor Interaction, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark Department of Pharmacology, University College London, London, UK.
Pain. 2012 Feb;153(2):311-318. doi: 10.1016/j.pain.2011.10.008. Epub 2011 Nov 17.
The activation of 5-hydroxytryptamine-3 (5-HT-3) receptors in spinal cord can enhance intrinsic spinal mechanisms of central hypersensitivity, possibly leading to exaggerated pain responses. Clinical studies suggest that 5-HT-3 receptor antagonists may have an analgesic effect. This randomized, double-blind, placebo-controlled crossover study tested the hypothesis that the 5-HT-3 receptor antagonist tropisetron attenuates pain and central hypersensitivity in patients with chronic low back pain. Thirty patients with chronic low back pain, 15 of whom were women (aged 53 ± 14 years) and 15 men (aged 48 ± 14 years), were studied. A single intravenous injection of 0.9% saline solution, tropisetron 2mg, and tropisetron 5mg was administrated in 3 different sessions, in a double-blind crossover manner. The main outcome was the visual analogue scale (VAS) score of spontaneous low back pain before, and 15, 30, 60, and 90 minutes after drug administration. Secondary outcomes were nociceptive withdrawal reflexes to single and repeated electrical stimulation, area of reflex receptive fields, pressure pain detection and tolerance thresholds, conditioned pain modulation, and area of clinical pain. The data were analyzed by analysis of variance and panel multiple regressions. All 3 treatments reduced VAS scores. However, there was no statistically significant difference between tropisetron and placebo in VAS scores. Compared to placebo, tropisetron produced a statistically significant increase in pain threshold after single electrical stimulation, but no difference in all other secondary outcomes was found. A single-dose intravenous administration of tropisetron in patients with chronic low back pain had no significant specific effect on intensity of pain and most parameters of central hypersensitivity.
脊髓中 5-羟色胺-3（5-HT-3）受体的激活可以增强中枢敏化的内在脊髓机制，可能导致疼痛反应过度。临床研究表明，5-HT-3 受体拮抗剂可能具有镇痛作用。这项随机、双盲、安慰剂对照的交叉研究检验了这样一个假设，即 5-HT-3 受体拮抗剂托烷司琼可减轻慢性腰痛患者的疼痛和中枢敏化。研究了 30 名慢性腰痛患者，其中 15 名女性（年龄 53 ± 14 岁）和 15 名男性（年龄 48 ± 14 岁）。以双盲交叉方式，在 3 个不同的时间段内，分别给予 0.9%生理盐水溶液、托烷司琼 2mg 和托烷司琼 5mg 单次静脉注射。主要结局是给药前、给药后 15、30、60 和 90 分钟时自发腰痛的视觉模拟量表（VAS）评分。次要结局是单次和重复电刺激的伤害性撤回反射、反射感受野面积、压痛检测和耐受阈值、条件性疼痛调制以及临床疼痛面积。数据通过方差分析和面板多元回归进行分析。所有 3 种治疗均降低了 VAS 评分。然而，托烷司琼与安慰剂在 VAS 评分上无统计学差异。与安慰剂相比，托烷司琼单次电刺激后疼痛阈值明显升高，但其他次要结局无差异。慢性腰痛患者单次静脉注射托烷司琼对疼痛强度和大多数中枢敏化参数无明显特异性作用。
