Neurology
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Several recent randomized clinical trials have found that the medications being evaluated for neuropathic pain did not significantly differ from placebo for the primary efficacy endpoint, despite encouraging results from prior preclinical and clinical studies. It is unclear whether these trials were unsuccessful because the medications truly lack efficacy or whether characteristics of the trials compromised the demonstration of treatment benefits. ⋯ The results suggest that study characteristics may contribute to the outcomes of clinical trials of treatments for neuropathic pain and provide an impetus for investigating strategies for decreasing placebo response rates and thereby possibly increasing the likelihood of positive outcomes in trials of efficacious treatments.