A randomized, open-label study comparing the efficacy and safety of lidocaine patch 5% with celecoxib 200 mg in patients with pain from osteoarthritis of the knee

Abstract

Animal models of osteoarthritis (OA) pain suggest that upregulation of sodium (Na) channel expression in primary afferent neurons induced by joint inflammation may result in OA pain and hyperalgesia. Because the lidocaine patch 5% acts by blocking abnormally functioning Na channels and decreasing ectopic nociceptive pain signal transmission, it may produce an analgesic response when applied to arthritic joints. Therefore, the lidocaine patch 5% may provide a useful non-systemic treatment option for OA. The objective of this randomized, open-label, activecontrol, parallel-group study was to compare the efficacy of the lidocaine patch 5% with that of celecoxib 200 mg in treating pain from OA of the knee. After a 14-day washout period during which all analgesic medications were discontinued, 200 patients with unilateral or bilateral OA of the knee with an average daily pain intensity score 5 on a scale of 0 to 10 for 3 of 5 consecutive days and an OA severity score of 7 on a scale of 0 to 24 prior to the baseline visit were randomized to 12 weeks’ treatment with the lidocaine patch 5% (n 100) or celecoxib 200 mg (n 100). Patients receiving the lidocaine patch 5% applied 1 1/3 patches on each affected knee every 24 hours. Efficacy measures included the Western Ontario and McMaster Universities OA Index, the Brief Pain Index, the Pain Quality Assessment Scale, and global assessments of change in OA pain and treatment satisfaction. Quality-of-life evaluations included the Beck Depression Inventory and sleep quality. Assessments of safety included adverse events, skin assessments (lidocaine group only), laboratory tests, vital signs, and physical examination. Data from the study will be presented at the meeting. This study is funded by Endo Pharmaceuticals, Inc.