Faculty of Pharmacy, Department of Pharmacology, Mahidol University, Rajthevee, Bangkok, Thailand.
Ann Pharmacother. 2013 Jul-Aug;47(7-8):921-32. doi: 10.1345/aph.1R725. Epub 2013 Jun 4.
Data from an open-label trial suggest that mirtazapine might prove useful in treatment of fibromyalgia syndrome (FMS).
To obtain preliminary efficacy data of mirtazapine for estimation of sample size requirements for a Phase 2 clinical trial in FMS.
This 13-week randomized controlled trial compared the effects of mirtazapine 15 mg/day, mirtazapine 30 mg/day, and placebo in 40 patients with FMS. The primary outcomes were change in Pain Visual Analog Scale (PVAS) and proportion of pain responders (≥30% PVAS reduction). Secondary outcomes included scores from the Jenkins Sleep Scale (JSS), Patient Global Impression of Change (PGIC), Fibromyalgia Impact Questionnaire (FIQ), Hamilton Depression Rating Scale (HAM-D), Patient Global Assessment, and self-reported adverse events.
Significant within-group PVAS reductions from baseline were observed in all 3 groups, with the greatest improvement in the mirtazapine 30-mg group (p < 0.005); between-group difference was not significant. The proportion of pain responders did not meet significance criteria (66.67% for mirtazapine 30 mg, 50% for mirtazapine 15 mg, 41.67% for placebo). Significant within-group improvement in JSS scores was seen for mirtazapine 30 mg (p < 0.01) and mirtazapine 15 mg (p < 0.05). Between-group comparison achieved significance for JSS item 3, waking several times per night (p < 0.05). On the PGIC, 72.73% felt better with both mirtazapine dosages compared with 50% for placebo. Within-group FIQ responses indicated improvement in only mirtazapine-treated groups, whereas within-group improvement for HAM-D and Patient Global Assessment was observed in all groups. Based on our findings, the sample size requirement (80% power, 5% type I error) should be 83 per group to detect PVAS change difference between mirtazapine 30 mg and placebo. Common mirtazapine-related adverse events were increased appetite and weight gain.
Patients with FMS taking mirtazapine exhibited within-group significant improvement in most of the measured outcomes. Between-group analysis was predictably compromised by the small sample size. Mirtazapine was well tolerated. Further study with a larger sample size is likely to be useful.
一项开放标签试验的数据表明，米氮平可能对纤维肌痛综合征（FMS）的治疗有用。
获得米氮平治疗纤维肌痛综合征的初步疗效数据，以便估计 FMS 二期临床试验的样本量需求。
这是一项为期 13 周的随机对照试验，比较了米氮平 15mg/天、米氮平 30mg/天和安慰剂在 40 例纤维肌痛综合征患者中的疗效。主要结局是疼痛视觉模拟量表（PVAS）的变化和疼痛应答者的比例（≥30%的 PVAS 降低）。次要结局包括詹金斯睡眠量表（JSS）评分、患者整体变化印象（PGIC）、纤维肌痛影响问卷（FIQ）、汉密尔顿抑郁评定量表（HAM-D）、患者总体评估和自报不良事件。
所有 3 组患者的 PVAS 基线均有显著的组内降低，米氮平 30mg 组的改善最大（p<0.005）；组间差异无统计学意义。疼痛应答者的比例未达到显著性标准（米氮平 30mg 组为 66.67%，米氮平 15mg 组为 50%，安慰剂组为 41.67%）。米氮平 30mg（p<0.01）和米氮平 15mg（p<0.05）组 JSS 评分均有显著的组内改善。JSS 项目 3（夜间醒来数次）的组间比较达到显著性（p<0.05）。PGIC 显示，与安慰剂组相比，72.73%的患者服用两种米氮平剂量后感觉更好。仅米氮平治疗组的 FIQ 反应表明有改善，而所有组的 HAM-D 和患者总体评估的组内改善。根据我们的发现，检测米氮平 30mg 与安慰剂之间 PVAS 变化差异的样本量需求（80%的功效，5%的Ⅰ类错误）应为每组 83 例。常见的米氮平相关不良事件是食欲增加和体重增加。
服用米氮平的纤维肌痛综合征患者在大多数测量结果中表现出组内显著改善。由于样本量小，组间分析不可避免地受到影响。米氮平耐受性良好。进一步的大样本研究可能会有所帮助。
