Diclofenac sodium gel effective for primary hand osteoarthritis

8 August 2009

Researchers from the University of California, Los Angeles, and Service de Rheumatologie, Hôpital Bichat, Paris, set out to measure the efficacy and safety of diclofenac sodium gel in patients with primary hand osteoarthritis (OA).

In a randomised, double-blind, placebo-controlled trial, men and women aged ≥ 40 years diagnosed with primary OA in the dominant hand were randomly assigned to self-apply topical 1% diclofenac sodium gel (Voltaren^® Gel) (n = 198) or vehicle (n = 187) to both hands 4 times daily for 8 weeks. Primary outcome measures included OA pain intensity (100 mm visual analog scale), total Australian/Canadian Osteoarthritis Hand Index (AUSCAN) score, and global rating of disease activity at 4 and 6 weeks. Secondary outcomes included onset of efficacy in Weeks 1 and 2, durability of efficacy at 8 weeks, measures of disease activity in the dominant hand, pain intensity in the non-dominant hand, AUSCAN subindices, end of study rating of efficacy, and Osteoarthritis Research Society International response criteria.

The researchers found that diclofenac sodium gel decreased pain intensity scores by 42–45%, total AUSCAN scores by 35–40%, and global rating of disease by 36–40%. Significant differences favouring diclofenac sodium gel over vehicle were observed at Week 4 for pain intensity and AUSCAN, with a trend for global rating of disease activity. At Week 6, diclofenac sodium gel treatment significantly improved each primary outcome measure compared with vehicle. Secondary outcomes generally supported the primary outcomes. The most common treatment-related adverse event (AE) was application-site paraesthesia. Most AE were mild. No cardiac events, gastrointestinal bleeding, or ulcers were reported.

The researchers concluded that topical diclofenac sodium gel was generally well tolerated and effective in primary hand OA.

(Source: Journal of Rheumatology: August 2009)