Topical nonsteroidal anti-inflammatory drug eases symptoms of osteoarthritis of the knee

Symptoms of primary osteoarthritis of the knee, including pain and stiffness, were significantly improved in patients who used a topical nonsteroidal anti-inflammatory drug (NSAID), according to an article in the October 11 issue of The Archives of Internal Medicine.

According to the article, nonsteroidal anti-inflammatory drugs (NSAIDs) are recommended for treating symptoms of osteoarthritis (OA), a joint disease affecting an increasingly large percentage of the aging population. However, oral NSAIDs carry the common risk of adverse effects on the gastrointestinal (GI) tract, the liver, and the kidneys. Topical NSAIDs may offer an alternative oral medication with a reduction in adverse effects, especially on the GI tract, the article states.

Sanford H. Roth, M.D., of Arizona Research & Education, Phoenix, and colleagues tested the efficacy of a topical diclofenac sodium solution (an NSAID) in the treatment of knee OA. The trial was conducted from December 2000 to May 2001 and studied 228 men and women aged 40 to 85 years with primary OA in at least one knee. Patients were randomized to receive 40 drops of the diclofenac solution applied to the affected knees or a control solution four times daily during the 12-week study.

The researchers found that the topical diclofenac solution was significantly more effective than the control solution in improving symptoms of knee osteoarthritis. Patients who applied the diclofenac solution experienced a 45.7 percent reduction in their ratings of knee pain. Scores on scales rating physical function and stiffness also improved by 36.7 percent and 35.1 percent, respectively. Patients in the diclofenac group also experienced a 45 percent improvement in the score for pain with walking.

Most adverse effects related to using the diclofenac were skin reactions at the site of application. Sixty-eight people (41.5 percent) using the diclofenac solution experienced minor skin irritation. In both the diclofenac and control groups, dry skin and rash were most frequent, occurring in 60 of 164 of those using diclofenac, and 18 of 164 of people using the control solution.

The authors write: "This study demonstrates that topical diclofenac solution …effectively treats symptoms of primary OA of the knee. Superior efficacy compared with the vehicle-control solution was demonstrated for all defined efficacy variables--[scaled] pain, physical function, and stiffness subscales; pain on walking, and a patient global assessment."