Abstract: For this update we added 14 new included studies (3489 participants), and excluded four studies. We also identified 20 additional reports of completed or ongoing studies that have not been published in full. The earlier review included 47 studies. This update included 61 studies. Most compared topical NSAIDs in the form of a gel, spray, or cream with a similar topical placebo; 5311 participants were treated with a topical NSAID, 3470 with placebo, and 220 with an oral NSAID. This was a 63% increase in the number of included participants over the previous version of this review. We also identified a number of studies in clinical trial registries with unavailable results amounting to about 5900 participants for efficacy and 5300 for adverse events. Formulations of topical diclofenac, ibuprofen, ketoprofen, piroxicam, and indomethacin demonstrated significantly higher rates of clinical success (more participants with at least 50% pain relief) than matching topical placebo (moderate or high quality data). Benzydamine did not. Three drug and formulation combinations had NNTs for clinical success below 4. For diclofenac, the Emulgel® formulation had the lowest NNT of 1.8 (95% CI 1.5 to 2.1) in two studies using at least 50% pain intensity reduction as the outcome. Diclofenac plasters other than Flector® also had a low NNT of 3.2 (2.6 to 4.2) based on good or excellent responses in some studies. Ketoprofen gel had an NNT of 2.5 (2.0 to 3.4), from five studies in the 1980s, some with less well defined outcomes. Ibuprofen gel had an NNT of 3.9 (2.7 to 6.7) from two studies with outcomes of marked improvement or complete remission. All other drug and formulation combinations had NNT values above 4, indicating lesser efficacy. There were insufficient data to compare reliably individual topical NSAIDs with each other or the same oral NSAID. Local skin reactions were generally mild and transient, and did not differ from placebo (high quality data). There were very few systemic adverse events (high quality data) or withdrawals due to adverse events (low quality data). Topical NSAIDs provided good levels of pain relief in acute conditions such as sprains, strains and overuse injuries, probably similar to that provided by oral NSAIDs. Gel formulations of diclofenac (as Emugel®), ibuprofen, and ketoprofen, and some diclofenac patches, provided the best effects. Adverse events were usually minimal. Since the last version of this review, the new included studies have provided additional information. In particular, information on topical diclofenac is greatly expanded. The present review supports the previous review in concluding that topical NSAIDs are effective in providing pain relief, and goes further to demonstrate that certain formulations, mainly gel formulations of diclofenac, ibuprofen, and ketoprofen, provide the best results. Large amounts of unpublished data have been identified, and this could influence results in updates of this review.

Plain-language summary: We searched medical databases for clinical trials comparing topical NSAIDs with placebo (creams or gels that do not contain a medicine) or other medicines in adults aged 16 years or older with musculoskeletal pain (typically sports injuries). The evidence is current to February 2015. This review is an update of 'Topical NSAIDs for acute pain in adults' originally published in Issue 6, 2010. We identified 14 new studies to add to the 47 studies included in the earlier review. We also identified 14 studies in a clinical trial registry that are completed and three short reports from meetings, for which we could not find full details (about 4500 participants). Three more studies are ongoing (almost 900 participants). The 61 included studies, involving 8386 participants, were generally of high-quality. They tested a number of different topical drugs, mostly against a topical placebo (carrier without the NSAID), with application at least once a day. We were interested in participants having good pain reduction (by about half) around seven days after treatment started. At later times, most people are expected to get better even without treatment. We looked at particular formulations of individual drugs. Gel formulations of diclofenac and ketoprofen were among the most effective, along with ibuprofen gel and diclofenac plaster. For diclofenac and ketoprofen gels, 7 or 8 people out of 10 with a painful strain, sprain, or muscle pull had much reduced pain after seven days, compared with only 2 or 3 out of 10 with placebo (high quality data). Other NSAIDs and formulations were better than placebo, but not by as much. Because both topical NSAIDs and topical placebo are rubbed into the skin in these studies, we know that any effect is not just from rubbing. About 1 in 20 people experienced a mild and short-lived side effect like redness at the application site. This was the same for topical NSAID and topical placebo (high quality data). Side effects like a stomach upset or feeling sick were uncommon, with no difference between topical NSAID and topical placebo (high quality data). There were no serious side effects.