SAN DIEGO — A topical pain-relieving cream found to be safe and effective for knee osteoarthritis in a double-blind controlled study may offer a new approach to treatment that avoids the cardiovascular and gastrointestinal hazards of many oral agents, according to Dr. Thomas J. Schnitzer.
Topical civamide cream 0.075% (Winston Laboratories, Vernon Hills, Ill.) was tested in a multicenter study that included 695 patients with radiographically confirmed osteoarthritis who ranged in age from 40 to 75 years.
At baseline, all study participants had a Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score greater than 9 (out of a total 20), despite treatment with NSAIDs or cyclo-oxgenase-2 (COX-2) inhibitors.
They were randomized to a regimen of civamide cream 0.075% to be applied three times daily, or a control cream containing low-dose (0.01%) civamide.
Blinding was therefore maintained, as both creams cause an initial burning sensation, Dr. Schnitzer reported in a late-breaking abstract session at the annual meeting of the American College of Rheumatology.
The three primary efficacy variables were WOMAC pain, WOMAC physical function, and subject global evaluation, and the primary efficacy analysis was the time-weighted average of change from baseline to day 84.
Statistically significant differences were seen in all variables and on the time-weighted average between the two groups at the conclusion of the study, wrote Dr. Schnitzer, professor of medicine at Northwestern University, Chicago.
The time-weighted average of change from a baseline mean score of 11.97 for WOMAC pain was 3.64 in the active treatment group, compared with a change of 3.3 from a baseline of 11.75 in the control group.
For WOMAC function, the time-weighted average change was 9.99 from a baseline of 38.88 in the active treatment group, while in the control group there was a change of 8.21 from a baseline of 38.2. Significant differences also were seen at the majority of interim time points, which were days 21, 42, and 63.
Dr. Schnitzer disclosed that he has received research grants and consulting fees from Winston Laboratories.