SOURCES: Arthritis Foundation: "Rub It On: Topical Analgesics." Gammaitoni, A . Current Medical Research and Opinion, 2004. Towheed, T. Journal of Rheumatology . 2006. Fidelix, T. Cochrane Database of Systematic Reviews, 2006. Galer B, Kivitz A, Fairfax M, et. al. "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:" Presented at the 24th Annual Scientific Meeting of the American Pain Society, March 30-April 2, 2005.
Although the mechanism of action of the topical medicinal plant products provides a rationale basis for their use in the treatment of osteoarthritis, the quality and quantity of current research studies of effectiveness are insufficient. Arnica gel probably improves symptoms as effectively as a gel containing non-steroidal anti-inflammatory drug, but with no better (and possibly worse) adverse event profile. Comfrey extract gel probably improves pain, and Capsicum extract gel probably will not improve pain or function at the doses examined in this review. Further high quality, fully powered studies are required to confirm the trends of effectiveness identifed in studies so far.