Topical diclofenac: clinical effectiveness and current uses in osteoarthritis of the knee and soft tissue injuries

Expert Opin Pharmacother. 2008 Nov;9(16):2921-9. Banning M.

BACKGROUND: Diclofenac is a commonly used non-steroidal anti-inflammatory drug (NSAID) for symptom control in osteoarthritis (OA) of the knee and soft tissue injuries. Although treatment with oral diclofenac is associated with serious adverse effects involving both the gastrointestinal and renal systems, these adverse effects are thought to be limited with topical diclofenac formulations without loss of efficacy. OBJECTIVE: The aim of this review is to explore the available evidence in relation to the pharmacokinetics, efficacy and reported adverse effects of the topical diclofenac formulations available. RESULTS/CONCLUSIONS: In the majority of studies examined, topical diclofenac formulations with sodium lotion, lecithin or epolamine gel, patch or plaster were either superior or equivalent to oral diclofenac formulations or placebo. Topical diclofenac significantly reduced pain and morning stiffness and improved physical function and patient global assessment without major adverse effects reported in patients with OA of the knee; and provided significant pain relief in patients with sports and soft tissue injuries involving the ankle, knee or shoulder. In the majority of studies, the predominant adverse effect involved pruritus or rash at the site of application, or nausea. The principle outcome of these studies is that topical diclofenac is a safe and practical alternative as a method of treatment in OA of the knee or as an alternative treatment for sports and soft tissue injury.