Topical diclofenac in the treatment of osteoarthritis of the knee

Niklas Schuelert, Fiona A Russell, Jason J McDougallDepartment of Physiology and Pharmacology, University of Calgary, Calgary, AB, CanadaAbstract: Osteoarthritis (OA) is a common disease that affects millions of people worldwide. As there is no cure for OA, drug treatment to relieve symptoms is the main form of management. Nonsteroidal anti-inflammatory drugs (NSAIDs) such as diclofenac are the most commonly used drugs to treat knee OA pain. Unfortunately, these agents are associated with gastrointestinal and cardiovascular risks, which limit their chronic use. Topical NSAIDs are emerging as a viable alternative for managing OA pain. Because a pharmacologically effective dose can be restricted to the site of pain, there is superfluous systemic absorption, and the risk of related adverse effects is minimized. This article reviews the currently available preclinical and clinical information on topical diclofenac for the treatment of OA pain, including data from recently published randomized controlled trials regarding the efficacy and safety of topical diclofenac. Most studies confirm topical diclofenac to be as effective as oral diclofenac with significantly reduced side effects; however, the efficacy of NSAIDs is far from optimal, and more research needs to be done to investigate the underlying mechanisms of OA in order to improve treatment options, especially for patients with NSAID-resistant OA pain.Keywords: osteoarthritis, topical diclofenac, NSAID, joint pain