Topical analgesics for neuropathic pain: an evidence-informed guide for the practicing clinician

To evaluate available evidence for the efficacy and safety of topical analgesics for neuropathic pain and to offer treatment guidance.

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.

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.

Recommendations were based on a survey and grading of existing literature and, when strong evidence was lacking, the collective clinical expertise of panelists.