Prescription Topical Anti-inflammatory Gels
Diclofenac diethylamine gel (Voltaren gel) has been used for relief of knee OA and other conditions in Europe since 1985. Diclofenac 1% gel was approved for use in knee OA in the United States in 2007.
In a randomized double blind placebo controlled three week study of the efficacy and safety of 1.16% diclofenac gel vs. placebo researchers found that the diclofanac gel was significantly more effective than the placebo. Over the first two weeks patients in the treatment group had an average improvement of 4mm on the visual analogue scale. The treatment vs. placebo was also more effective as detected by analyses of the WOMAC and OARSI scores as well. The diclofenac gel was effective over the first week, reached its peak during the second week, and maintained its efficacy during the third week.11
Similar data was found in a randomized, double blind, controlled study of the efficacy of diclofenac sodium 1% gel vs. a placebo for treatment of knee OA. Researchers found that the diclofenac gel was 25% more effective at reducing pain, 37% more effective at improving physical function, and 47% more effective at improving global rating of disease vs. placebo.8