Collaku Agron, Yue Yong, Reed Kenneth
GlaxoSmithKline Consumer, Healthcare, Parsippany, NJ, USA.
J Pain Res. 2017 Mar 21;10:669-678. doi: 10.2147/JPR.S126296. eCollection 2017.
BACKGROUND/OBJECTIVE: Guaifenesin, an over-the-counter (OTC) expectorant, has exhibited muscle relaxant effects preclinically and clinically. This proof-of-principle study explored whether OTC doses of guaifenesin can provide relief from acute upper back, neck, or shoulder muscle spasm and pain.
This multicenter, placebo-controlled, repeat-dose, parallel study randomly assigned adults experiencing acute pain and muscle spasm in their upper back, neck, or shoulder to guaifenesin 600 or 1200 mg or matched placebo twice daily (BID) in a 2:2:1:1 ratio for 7 days. The primary end point was the change from baseline in muscle spasm relief, measured using an 11-point numeric rating scale (0=not present to 10=unbearable) recorded twice daily and averaged over the 7-day treatment period. Analyses were performed using a linear mixed model that included treatment as a fixed effect and site as a random effect.
A total of 77 subjects were included in the 4 treatment groups. Least squares mean muscle spasm score over 7 days was 1.77 with guaifenesin 1200 mg, 1.42 with its matched placebo, 1.53 with guaifenesin 600 mg, and 1.74 with its matched placebo. Treatment with guaifenesin 1200 mg BID provided 25% greater reduction in mean muscle spasm over its matched placebo and 16% greater reduction than guaifenesin 600 mg BID. These differences were not statistically significant. Based on comparisons of absolute mean values, a consistent directional change in effect was observed, suggesting some benefit from placebo to lower-to-upper doses of guaifenesin with regard to muscle spasm, tension, pain, discomfort, and relaxation. No severe or serious adverse events were reported.
Results suggest the potential for OTC dose of guaifenesin 1200 mg BID to provide symptomatic relief of upper back musculoskeletal pain and spasm. Confirmation of this preliminary result in a larger, adequately powered study is needed.
背景/目的：愈创甘油醚是一种非处方祛痰剂，在临床前和临床研究中均显示出肌肉松弛作用。本原理验证研究探讨了非处方剂量的愈创甘油醚是否能缓解急性上背部、颈部或肩部肌肉痉挛和疼痛。
本多中心、安慰剂对照、重复给药、平行研究将患有急性上背部、颈部或肩部疼痛和肌肉痉挛的成年人随机分为两组，分别给予600毫克或1200毫克愈创甘油醚或匹配的安慰剂，每日两次，比例为2:2:1:1，持续7天。主要终点是肌肉痉挛缓解程度相对于基线的变化，使用11点数字评分量表（0 = 不存在至10 = 难以忍受）进行测量，每天记录两次，并在7天治疗期内进行平均。分析采用线性混合模型，将治疗作为固定效应，将研究地点作为随机效应。
4个治疗组共纳入77名受试者。7天内，1200毫克愈创甘油醚组的最小二乘平均肌肉痉挛评分为1.77，其匹配安慰剂组为1.42，600毫克愈创甘油醚组为1.53，其匹配安慰剂组为1.74。每日两次服用1200毫克愈创甘油醚比其匹配安慰剂组的平均肌肉痉挛缓解程度高25%，比每日两次服用600毫克愈创甘油醚组高16%。这些差异无统计学意义。基于绝对均值的比较，观察到效应有一致的方向性变化，表明从安慰剂到低剂量至高剂量的愈创甘油醚在肌肉痉挛、紧张、疼痛、不适和放松方面有一定益处。未报告严重或重大不良事件。
结果表明，每日两次服用1200毫克非处方剂量的愈创甘油醚有可能缓解上背部肌肉骨骼疼痛和痉挛的症状。需要在更大规模、有足够效力的研究中证实这一初步结果。
