Lidocaine patch for treatment of acute localized pain in the emergency department: a systematic review and meta-analysis.

Abstract

Lidocaine patches are commonly prescribed for acute localized pain. Most of the existing evidence is, however, derived from postoperative or chronic pain. The objective of this study is to assess the efficacy and safety of lidocaine patch compared to placebo patch or nonsteroidal anti-inflammatory drugs (NSAIDs) for acute localized pain. This was a systematic review and meta-analysis of trials randomizing patients with acute localized pain to lidocaine patch versus placebo patch or NSAIDs. The outcomes were change in pain score (any validated scale) from baseline to a specific time endpoint (primary efficacy); adverse events (primary harm), and time to exit the study due to reaching a pain relief target (secondary). We used Cochrane revised tool to assess the risk of bias and GRADE to rate the quality of evidence. The meta-analysis was performed using a random-effects model and Cochrane Q test for heterogeneity. Data were summarized as risk ratios and weighted mean differences with 95% confidence interval (CI). We conducted a comprehensive search of MEDLINE, EMBASE, and other major databases, identifying 10 randomized controlled trials with a total of 523 patients. These trials collectively found that lidocaine patches were more effective in controlling both musculoskeletal and neuropathic pain compared to placebo patches. Due to heterogeneity among the studies, we did not pool the efficacy data. The risk of adverse events was similar between the groups (risk ratio: 0.90; 95% CI: 0.48-1.67; moderate-quality evidence). In the two trials comparing lidocaine patches with NSAIDs, there was no statistically significant difference in pain relief between the treatments. Low to moderate-quality evidence from small trials supports the efficacy and safety of lidocaine patch for the treatment of acute localized pain.