Svensson Peter, Wang Kelun, Arendt-Nielsen Lars
Department of Clinical Oral Physiology, Dental School, Aarhus University, DK-8000 Aarhus C, Denmark.
Eur J Pain. 2003;7(5):449-56. doi: 10.1016/S1090-3801(03)00013-2.
A randomised, double-blind, placebo-controlled three-way cross-over study was performed to investigate the effect of two muscle relaxants (tolperisone hydrochloride and pridinol mesilate) on experimental jaw-muscle pain and jaw-stretch reflexes. Fifteen healthy men participated in three randomised sessions separated by at least 1 week. In each session 300 mg tolperisone, 8 mg pridinol mesilate or placebo was administered orally as a single dose. One hour after drug administration 0.3 ml hypertonic saline (5.8%) was injected into the right masseter to produce muscle pain. Subjects continuously rated their perceived pain intensity on an electronic 10-cm visual analogue scale (VAS). The pressure pain threshold (PPT) was measured and short-latency reflex responses were evoked in the pre-contracted (15% maximal voluntary contraction) masseter and temporalis muscles by a standardised stretch device (1 mm displacement, 10 ms ramp time) before (baseline), 1 h after medication (post-drug), during ongoing experimental muscle pain (pain-post-drug), and 15 min after pain had vanished (post-pain). Analysis of variance demonstrated significantly lower VAS peak pain scores (5.9 +/- 0.4 cm) after administration of tolperisone hydrochloride compared with pridinol mesilate (6.8 +/- 0.4 cm) and placebo (6.6 +/- 0.4 cm) (P=0.020). Administration of pridinol mesilate was associated with a significant decrease in PPTs compared with tolperisone hydrochloride and placebo (P=0.002) after medication, but not after experimental jaw-muscle pain. The normalised peak-to-peak amplitude of the stretch reflexes were not significantly influenced by the test medication (P=0.762), but were in all sessions significantly facilitated during ongoing experimental jaw-muscle pain (P=0.034). In conclusion, tolperisone hydrochloride provides a small, albeit significant reduction in the perceived intensity of experimental jaw-muscle pain whereas the present dose had no effect on the short-latency jaw-stretch reflex.
进行了一项随机、双盲、安慰剂对照的三向交叉研究，以调查两种肌肉松弛剂（盐酸托哌酮和甲磺酸普立地诺）对实验性颌面部肌肉疼痛和颌部伸展反射的影响。15名健康男性参与了三个随机阶段，各阶段间隔至少1周。在每个阶段，口服300毫克盐酸托哌酮、8毫克甲磺酸普立地诺或安慰剂作为单剂量给药。给药1小时后，将0.3毫升高渗盐水（5.8%）注射到右侧咬肌中以产生肌肉疼痛。受试者通过电子10厘米视觉模拟量表（VAS）持续评定他们感知到的疼痛强度。测量压力疼痛阈值（PPT），并在基线、用药后1小时、实验性肌肉疼痛期间（疼痛用药后）以及疼痛消失后15分钟，使用标准化拉伸装置（1毫米位移，10毫秒斜坡时间）在预先收缩（最大自主收缩的15%）的咬肌和颞肌中诱发短潜伏期反射反应。方差分析表明，与甲磺酸普立地诺（6.8±0.4厘米）和安慰剂（6.6±0.4厘米）相比，给予盐酸托哌酮后VAS峰值疼痛评分显著更低（5.9±0.4厘米）（P= .020）。与盐酸托哌酮和安慰剂相比，用药后给予甲磺酸普立地诺与PPT显著降低相关（P= .002），但在实验性颌面部肌肉疼痛后则不然。测试药物对拉伸反射的归一化峰峰值幅度没有显著影响（P= .762），但在所有阶段，在实验性颌面部肌肉疼痛期间均显著增强（P= .034）。总之，盐酸托哌酮虽然作用较小，但能显著降低实验性颌面部肌肉疼痛的感知强度，而当前剂量对短潜伏期颌部伸展反射没有影响。
