Objective: Topical diclofenac is widely used in the treatment of pain and inflammation. This comprehensive review assesses the safety and efficacy of topical diclofenac in a range of painful and inflammatory disorders.
Methods: Double-blind, randomized, placebo- or active-controlled trials (RCT) evaluating topical diclofenac in soft-tissue injuries, soft-tissue rheumatic disorders and osteoarthritis were identified through detailed literature searches. In addition, non-RCT evidence from publications evaluating the pharmacologic characteristics of topical diclofenac were also included in this review to obtain a more complete picture of the drug's profile, its efficacy and safety.
Results: Studies demonstrate that the drug preferentially distributes to the target tissues in sufficient concentrations to produce a therapeutic effect. A total of 19 double-blind RCTs in more than 3000 patients, supported by single-blind or open trials, consistently show that topical diclofenac significantly reduces pain and inflammation in acute and chronic conditions compared with placebo and is comparable to other topical non-steroidal anti-inflammatory drugs (NSAIDs) and some oral NSAIDs (diclofenac, ibuprofen, naproxen). Improvements have also been observed in patients' functional capacity and mobility. Topical diclofenac is well tolerated, resulting mostly in mild, easily resolved local skin irritation, and is associated with fewer side-effects than other topical NSAIDs and a lower rate of gastrointestinal complications than oral NSAIDs (diclofenac, ibuprofen, naproxen).
Conclusion: This evidence-based review shows topical diclofenac to be an effective and well tolerated treatment in painful and inflammatory conditions, at least in the short-term. However, only published RCT studies have been included in this analysis, which may exclude some interesting data from non-RCT studies. Future trials of topical diclofenac need to be of longer duration, be better reported and consider a broader spectrum of acute and chronic pain indications.