(dailyRx News) Osteoarthritis is commonly treated with non-steroidal anti-inflammatory drugs (NSAIDs). For the most part, NSAIDs are taken orally, or through the mouth. But that's not the only way patients can take these drugs.
Topical NSAIDs - which come as gels, creams or patches - may relieve pain in patients with osteoarthritis of the knee or hands.
In fact, applying NSAIDs to the skin seems to work just as well taking them orally.
"Topical NSAIDs are widely used in some parts of the word for acute and chronic painful conditions, but have not been universally accepted until recently," said Sheena Derry, PhD, of the University of Oxford in the United Kingdom, and colleagues in background information of their study.
One reason topical NSAIDs may not be as popular could be that older studies on the topical form were generally short, the authors said.
When it comes to ongoing pain conditions like osteoarthritis, shorter studies do not provide enough information.
So, Dr. Derry and colleagues studied the use of topical NSAIDs in studies that lasted at least 8 weeks.
The researchers found that topical NSAIDs reduced the pain of chronic musculoskeletal conditions better than placebo.
They noted that the best data they could find was for the use of topical diclofenac (sold as Flector, Solaraze, Pennsaid and Voltaren) in patients with osteoarthritis. They studied two forms of diclofenac: the solution form and the gel form.
"For every six participants treated with diclofenac solution, one will experience a good level of pain relief over 8 to 12 weeks; with diclofenac gel, 11 participants need to be treated for one to benefit," the authors wrote.
Compared to placebo or oral NSAIDs, topical NSAIDs led to an increase in mild side effects, mainly skin reactions. Topical NSAIDs were not associated with an increase in serious side effects.
In addition, topical NSAIDs led to a reduction in gastrointestinal side effects, compared to NSAIDs taken by mouth.
"For every 16 participants treated with topical diclofenac, one is likely to experience a local skin reaction, and for every 50 treated, one will withdraw due to unacceptable problems," the authors wrote.
The 34 studies reviewed by Dr. Derry and colleagues included 7,688 participants. Of these studies, 23 compared the use of topical NSAIDs to placebo.
The review was published September 12 in The Cochrane Library.