Presented at the 2012 AAPM Annual Meeting « Back

Efficacy of Diclofenac Sodium Topical Solution Compared with Oral Diclofenac: A By-Question Analysis of Three WOMAC® Dimensions in Patients with Osteoarthritis of the Knee

Sanford H. Roth, MD, sroth16@cox.net¹, Philip Fuller, PharmD², (1) Arthritis Research Laboratory, Paradise Valley, Arizona, (2) Covidien, Hazelwood, Missouri

Introduction: Patient responses to the individual questions of the WOMAC® pain, physical function, and stiffness subscales were analyzed to identify potential differences between diclofenac sodium topical solution (TDiclo) and oral diclofenac (ODiclo) in osteoarthritis (OA) of the knee. Materials and Methods: In this 12-week, double-blind, randomized, controlled trial, patients applied 40 drops of solution four times/day and took one tablet daily. Treatment groups were: TDiclo, vehicle, placebo, ODiclo (100 mg), and TDiclo + ODiclo. Patients provided written informed consent, and the study was conducted with Institution Review Board approval. Results: In total, 305 patients were included (154 TDiclo, 151 ODiclo). Mean (SD) change from baseline in WOMAC pain score was -6.02 (4.54) for TDiclo and -6.43 (4.11) for ODiclo (P = 0.42), one with no significant differences for the five component questions. Mean change from baseline in WOMAC physical function was -15.7 (15.1) for TDiclo and -17.5 (14.4) for ODiclo (P=0.31), one with no significant differences between treatments for the eight component questions. There was no difference between treatments in change from baseline for WOMAC stiffness overall (-1.93 TDiclo vs. -2.07 ODiclo; P=0.59), one on first waking (-0.99 vs. -1.03; P = 0.97), or after resting (-0.94 vs. -1.05; P=0.28). AEs most frequently leading to discontinuation were application-site reactions with TDiclo (3.2%) and gastrointestinal AEs with ODiclo (7.3%). Conclusions: TDiclo demonstrated similar efficacy to ODiclo for OA of the knee according WOMAC pain, physical function, and stiffness overall and component question scores. References: 1)Simon LS, Grierson LM, Naseer Z, et al. Efficacy and safety of topical diclofenac containing dimethyl sulfoxide (DMSO) compared with those of topical placebo, DMSO vehicle and oral diclofenac for knee osteoarthritis. Pain. 2009;43:238-245.

Funding: Statistical analysis was provided by ProSoft Solutions LLC. Technical editorial and medical writing support was provided by Synchrony Medical, LLC, West Chester, PA. This support was funded by Mallinckrodt Inc., a Covidien Company, Hazelwood, MO.