RESUMO
Background: Surveys of back pain sufferers in the United States, China, Russia, and Germany were performed to better understand self-reported causes of acute nonspecific back pain and acute lower back pain among individuals engaging in sports and their preferred treatments. Methods: In each country, 1000 participants were surveyed (Step 1) to identify a population of nonspecific acute back pain sufferers, understand pain and treatment characteristics, and generate profiles for individuals with long-lasting (≥7 days) acute lower back pain. Subsequently, 200 participants with acute lower back pain episodes (7-21 days) and sports participation were identified in each country and completed surveys (Step 2) about sociodemographic, pain, treatment characteristics, and causes/triggers of long-lasting acute lower back pain episodes. Results: In the United States, China, Russia, and Germany, respectively, 59%, 49%, 61%, and 63% of respondents reported ≥1 episode of nonspecific acute back pain in the previous 6 months. Average numbers of monthly nonspecific acute back pain episodes in the United States, Russia, Germany, and China were 2.5, 1.8, 1.3, and 0.8, respectively. Prevalence of acute lower back pain associated with sports/leisure activities ranged from 20% (Russia and Germany) to 46% (China). Onset of long-lasting acute lower back pain was between ages 30 and 33 years, limiting usual activities and reducing walking distance in 60% to 85% of respondents across all countries. Acute lower back pain started post-exercise within the first day for ≥75% of respondents. Most popular nonprescription and prescription treatments for acute lower back pain were creams/gels in Russia, creams/gels and oral painkillers in Germany, oral painkillers in the United States, and hot/cold patches in China. Conclusion: These results help to better understand acute back pain triggers, features, and treatment preferences among sports participants in different countries. Further research is warranted to develop preventative strategies. Trial Registration: Not applicable.
RESUMO
BACKGROUND: Topical diclofenac, a nonsteroidal anti-inflammatory drug, has proven efficacy and safety in the management of osteoarthritis pain. We investigated penetration of topical diclofenac into knee synovial tissue and fluid (primary objective) and evaluated relative exposure in the knee versus plasma (secondary objective). METHODS: In this phase I, double-blind, multicenter study, patients scheduled for arthroplasty for end-stage knee osteoarthritis were randomly assigned 2:1 to 4 g diclofenac diethylamine 2.32% w/w gel (92.8 mg diclofenac diethylamine, equivalent to 74.4 mg diclofenac, per application) or placebo gel, applied to the affected knee by a trained nurse/designee every 12 h for 7 days before surgery. Diclofenac concentrations were measured in synovial tissue, synovial fluid and plasma from samples obtained during surgery ⩾12 h after last application. Treatment-emergent adverse events (TEAEs) were evaluated. RESULTS: Evaluable synovial tissue or fluid samples were obtained from 45 (diclofenac n = 29; placebo n = 16) of 47 patients. All diclofenac-treated participants had measurable diclofenac concentrations in synovial tissue [geometric mean 1.57 (95% confidence interval (CI) 1.12, 2.20) ng/g] and fluid [geometric mean 2.27 (95% CI 1.87, 2.76) ng/ml] ⩾12 h after the last dose. Geometric mean (95% CI) ratio of diclofenac in synovial tissue:plasma was 0.32 (0.23, 0.45) and in synovial fluid:plasma was 0.46 (0.40, 0.54). TEAE rates were similar for diclofenac (55.2%) and placebo (58.8%); none were treatment related. CONCLUSIONS: Topical diclofenac diethylamine 2.32% w/w gel penetrated into the osteoarthritic knee after repeated application and remained detectable in synovial tissue and fluid at the end of the final 12 h dosing cycle.