Taking a medication by mouth is not the only way to deliver chemicals into the body. The skin is capable of absorbing chemicals both toxic, in the case of hazardous material, and therapeutic, in the case of medications. The effectiveness of transdermal absorption depends on the area of application, the skin characteristics, the chemical compound, and base substrate that provides a "vehicle" for penetration. Many types of medications can be administered in a topical application like hormones, opioids, anesthetics, and now anti-inflammatory medications. Actually, the delivery of medications through the skin is nothing new because compounding pharmacies can make custom topical medications. However, the cost of custom compounded medications is prohibitive for most people. But now, the topical anti-inflammatory medications are available commercially for a greater number of people.
For at least ten years, topical anti-inflammatory medications have been reported to be effective at treating pain associated with: acute injury, rheumatoid arthritis, breast pain, and episiotomy pain. The current literature was just reviewed by the Cochrane Library which surmises that topical anti-inflammatory medications (diclofenac, ibuprofen, ketoprofen, piroxicam) are all effective and safe. In fact, upwards of 65% of users report pain relief, compared with 45% relief reported in those using a placebo. The only problem with the current data about topical anti-inflammatory medications is that there are no long-term outcomes studies proving the safety with prolonged use. So, it is unknown whether or not topical applications have the same potential for life-threatening problems found with oral anti-inflammatory medications. But judging by the minimal systemic concentrations of chemicals with small, localized topical applications, the long-term safety looks promising. The most common side effects have been localized reactions. Relieving pain while avoiding the systemic side effects makes topical anti-inflammatory medications a very worthwhile option.
Three popular options all contain diclofenac. The first option, Voltaren Gel, has fallen out of favor after the FDA issued a warning about the potential for liver damage. Besides, the delivery system for the diclofenac medication really lacks penetration power. Thus, the "next generation" of topical diclofenac was approved in 2009 and is called Pennsaid. The "vehicle base" in Pennsaid that allows the anti-inflammatory chemical to hitch a ride through the skin is called DMSO (Dimethylsulfoxide). With better penetration, the dilofenac can get down deep into a painful area like a joint or muscle. Pennsaid seems to be the "better generation" of topical anti-inflammatory medications which work just as well as oral medications according to one report. But Pennsaid has competition. Another topical diclofenac is on the market and in a patch form instead of a liquid. This patch is called the Flector Patch. Over 50% of the users find the Flector Patch to be effective at relieving pain; whether or not that is a placebo effect is debatable. Either way, the pain relief is real and these topical anti-inflammatory medications are here to stay. Someday, these topicals might be available without a prescription if they prove to be safer than the pills found on the shelves today.