Chou Roger, Carson Susan, Chan Benjamin K S
Oregon Evidence-based Practice Center, 3181 SW Sam Jackson Park Road, Mail code: BICC, Portland, OR 97239, USA.
J Gen Intern Med. 2009 Feb;24(2):178-88. doi: 10.1007/s11606-008-0877-5. Epub 2008 Dec 17.
Previous systematic reviews concluded that tricyclics antidepressants are superior to gabapentin for neuropathic pain, but were based on indirect comparisons from placebo-controlled trials.
To evaluate gabapentin versus tricyclic antidepressants for diabetic neuropathy and post-herpetic neuralgia, using direct and indirect comparisons.
MEDLINE (1966 to March Week 4 2008), the Cochrane central register of controlled trials (1st quarter 2008), and reference lists.
We selected randomized trials directly comparing gabapentin versus tricyclic antidepressants or comparing either of these medications versus placebo.
Studies were reviewed, abstracted, and quality-rated by two independent investigators using predefined criteria.
We performed a meta-analysis of head-to-head trials using a random effects model and compared the results to an adjusted indirect analysis of placebo-controlled trials.
In three head-to-head trials, there was no difference between gabapentin and tricyclic antidepressants for achieving pain relief (RR 0.99, 95% CI 0.76 to 1.29). In adjusted indirect analyses, gabapentin was worse than tricyclic antidepressants for achieving pain relief (RR = 0.41, 95% CI 0.23 to 0.74). The discrepancy between direct and indirect analyses was statistically significant (p = 0.008). Placebo-controlled tricyclic trials were conducted earlier than the gabapentin trials, reported lower placebo response rates, had more methodological shortcomings, and were associated with funnel plot asymmetry.
Though direct evidence is limited, we found no difference in likelihood of achieving pain relief between gabapentin and tricyclic antidepressants for diabetic neuropathy and post-herpetic neuralgia. Indirect analyses that combine data from sets of trials conducted in different eras can be unreliable.
以往的系统评价得出结论，三环类抗抑郁药在治疗神经性疼痛方面优于加巴喷丁，但这些结论基于安慰剂对照试验的间接比较。
采用直接和间接比较的方法，评估加巴喷丁与三环类抗抑郁药治疗糖尿病性神经病变和带状疱疹后神经痛的疗效。
MEDLINE（1966年至2008年第3周）、Cochrane对照试验中心注册库（2008年第1季度）及参考文献列表。
我们选取了直接比较加巴喷丁与三环类抗抑郁药或比较这两种药物与安慰剂的随机试验。
由两名独立研究人员按照预先设定的标准对研究进行审查、提取摘要并进行质量评级。
我们采用随机效应模型对直接对比试验进行荟萃分析，并将结果与安慰剂对照试验的校正间接分析结果进行比较。
在三项直接对比试验中，加巴喷丁与三环类抗抑郁药在实现疼痛缓解方面无差异（相对危险度0.99，95%可信区间0.76至1.29）。在校正间接分析中，加巴喷丁在实现疼痛缓解方面比三环类抗抑郁药差（相对危险度 = 0.41，95%可信区间0.23至0.74）。直接分析与间接分析之间的差异具有统计学意义（p = 0.008）。安慰剂对照的三环类药物试验比加巴喷丁试验开展得更早，报告的安慰剂反应率更低，存在更多方法学缺陷，且与漏斗图不对称有关。
尽管直接证据有限，但我们发现加巴喷丁与三环类抗抑郁药在治疗糖尿病性神经病变和带状疱疹后神经痛时，实现疼痛缓解的可能性没有差异。合并不同时期进行的试验组数据的间接分析可能不可靠。
