Hirani, Salman

Abstract Objective To evaluate available evidence for the efficacy and safety of topical analgesics for neuropathic pain and to offer treatment guidance. Methods An expert panel searched PubMed (Medline) and reference lists of published articles for available literature assessing 8 categories of topical analgesics used to treat various neuropathic pain conditions. The panel rated the level of analgesic efficacy evidence for each treatment and considered safety, ease of use, and cost. The degree of consensus on the recommendations among the panelists was measured. Results There was strong evidence and high consensus that capsaicin 8% is effective for diabetic peripheral neuropathy and postherpetic neuralgia and that lidocaine is effective for postherpetic neuralgia. There was strong evidence and moderate consensus that capsaicin 8% could be effective for HIV-induced neuropathy. There was moderate evidence and high consensus that lidocaine is likely effective for diabetic peripheral neuropathy, idiopathic neuropathy, and postsurgical neuropathy and that capsaicin 8% might be effective for chemotherapy-induced peripheral neuropathy and complex regional pain syndrome. Evidence was weak for other topical medications, though the panel strongly agreed that antidepressants might help with postherpetic neuralgia, complex regional pain syndrome, postsurgical neuropathy, and post-traumatic neuropathy; that nonsteroidal anti-inflammatory drugs could help with postsurgical neuropathy; and that gabapentin might benefit vulvodynia. There was less agreement about whether antidepressants might benefit diabetic peripheral neuropathy, chemotherapy-induced peripheral neuropathy, and vulvodynia and whether capsaicin 8% could be effective for postsurgical neuropathy. Conclusions Recommendations were based on a survey and grading of existing literature and, when strong evidence was lacking, the collective clinical expertise of panelists.

Abstract The availability of knowledge about the effects of buprenorphine on pain perception in healthy adults could help investigators select experimental tests with evidence of responsiveness to buprenorphine in nondiseased states. The purpose of this meta-narrative systematic review is to summarize the effects of buprenorphine on pain perception in healthy adults. Comprehensive database searches were conducted from inception dates through July 16, 2024. Inclusion criteria included all study designs involving healthy adults receiving buprenorphine and tests of pain perception. Risk of bias was assessed using a tool developed for randomized controlled trials (RCTs). A meta-narrative approach was used due to high levels of clinical heterogeneity. A total of 10 RCTs were included, and healthy adults comprised the comparator groups in all trials. Three RCTs had a low risk of bias, 6 had some concerns, and 1 had a high risk of bias. Six RCTs used intravenous buprenorphine, 3 used transdermal, and 1 study used intravenous and sublingual buprenorphine. The effects of buprenorphine on pain perception are influenced by the route of administration, dose, and pain stimulus modality. Considerable differences exist in the effects of intravenous and transdermal buprenorphine, but only 1 study used sublingual buprenorphine, which limited comparison with the other drug formulations. Based on these findings, recommendations for clinical trials are proposed. These recommendations should be cautiously interpreted due to the clinical heterogeneity, but they provide a framework for advancing the use of experimental pain tests in trials of buprenorphine involving comparator groups of healthy adults.