Nonsteroidal anti inflammatory drugs, also known as Nsaids, are commonly used for topical pain relief in Europe, and are available there as over-the-counter pain relief medications. Topical Nsaids are available as creams, gels, patches and sprays for joint and muscle pain relief. However, topical Nsaids were only approved a few years ago as prescription drugs in the United States, and consequently are not as widely known here.
Many Europeans rave about the efficacy of topical nonsteroidal anti inflammatory drugs, including Dr. Andrew Moore, a pain researcher from Oxford University who has studied topical pain relief for strain and sprain injuries using Nsaids. Researchers were initially skeptical about the effectiveness of these drugs, as well as concerned about Nsaid side effects. One reason for this was that previous studies on nonsteroidal anti inflammatory drugs were short and not well designed, casting doubts on their results. However, new studies using tight controls and comparing data across multiple drug trials suggest that topically applied Nsaids are as effective as orally administered pain medications for treatment of osteoarthritis, as well as for sore joints and tendinitis.
One advantage for topical pain relief treatments, including topical Nsaids, is that by applying them directly on the skin, we can bypass the digestive system and most of the bloodstream, thereby reducing side effects of these medications. However, oral Nsaid side effects have been documented. Orally administered Nsaid side effects include toxicity to the kidneys, as well as bleeding of the gastrointestinal tract. Bextra and Vioxx are two well-known examples of oral Nsaids that were discontinued as they were associated with strokes and heart attacks. The furor over Vioxx was a turning point in the acceptance of non steroidal inflammatory drugs as topical rather than oral pain relief treatment options.
Topical pain relief Nsaids may help elderly patients or those already taking multiple oral medications, who might not be able to take further pain treatments orally. Also, one study has found that Nsaid skin creams deliver very high concentrations of the topical pain reliever to the joints (much higher than when Nsaids are taken orally). Yet, the concentration that accumulates in the blood stream is quite low when applied topically (less than 5% of what is observed when taking Nsaids orally).
However, even topical Nsaid side effects are known. Skin creams based on topical Nsaids have been associated with a higher rate of skin irritation, rashes and redness. Another concern is that the Nsaid diclofenac, which when orally ingested has been implicated in liver damage, is found in all of the topical Nsaids sold so far in the US: the Flector patch, Voltaren gel and the liquid Pennsaid.
It is also not know whether topical nonsteroidal anti inflammatory drugs pose elevated risks to already vulnerable people, i.e., those who have other health problems including liver conditions, people on blood thinners, etc., since people with these conditions were not included in the clinical trials. One study found that 15% of older people reported gastrointestinal problems after being exposed to topical Nsaids, although their lives were not at risk.
Yet, in a trial comparing Nsaid side effects between topical and oral versions, those who took the oral Nsaids as pills had elevated rates of various conditions including diarrhea, anemia, indigestion and anomalous liver tests, compared to those who applied topical Nsaids as skin creams. So, even though topical Nsaid side effects are not nonexistent, at least they seem reduced compared to the orally taken ones. While additional rigorous studies need to be done to assess other serious Nsaid side effects, they do hold promise as treatment for osteoarthritis, joint and muscle pain relief and other conditions with fewer side effects than orally taken Nsaids, and will likely be prescribed more frequently in the US in future.