Results of this study provide strong evidence that topical nonsteroidal anti-inflammatory drugs work by mechanisms other than local massage, since this would have been provided by placebo as well. The consistency of the trials is striking, and the effect size of the pooled results is large.
An NNT of 3 means that one person in three will benefit from topical nonsteroidal anti-inflammatory drugs over and above the benefit from placebo. Canadian physicians might be justifiably reluctant to prescribe medication for a non-approved indication, even though many examples of such practices exist. Long-term safety data were not presented in the paper, but if available, they would provide a much higher comfort level for prescribing.
The problem of musculoskeletal pain is enormous and growing rapidly. Nonpharmacologic approaches are valuable but the pharmacologic armamentarium is extremely limited. After acetaminophen has been tried, the remaining medications are either narcotics or nonsteroidal anti-inflammatory drugs, each of which has its own potential problems.
Topical capsaicin is effective for some patients and might be worth trying. Newer cyclooxygenase-2 inhibitor nonsteroidal agents have recently become available, but their effectiveness and long-term adverse effect profile remain unclear. Their cost is substantially higher than the cost of many older agents.
Many patients continue to suffer with musculoskeletal pain despite use of currently available treatments. For them, we might be justified in trying topical NSAIDs after a thorough discussion of the potential advantages and adverse effects.
Topical nonsteroidal anti-inflammatory drugs could play a much larger role in treatment of acute and chronic musculoskeletal disorders if long-term safety data were available and if they received Canadian approval for these indications.