The effectiveness of topical diclofenac for lateral epicondylitis.

INTRODUCTION: Gastrointestinal upset and local pain commonly limit the use of oral nonsteroidal anti-inflammatory drugs and corticosteroid injection as treatments for lateral epicondylitis. Transdermal administration of an anti-inflammatory drug could avoid these adverse effects.

PURPOSE: To determine the effectiveness of topical diclofenac as a treatment of lateral epicondylitis.

METHODS: A convenience sample of 14 subjects meeting clinical criteria of chronic lateral epicondylitis participated in this randomized, double blind, crossover study. Each subject applied a pluronic lecithin liposomal organo-gel (PLO) over the affected lateral elbow three times daily for I week, followed by a 1-week "washout" period of no gel. A second topical PLO gel was then applied similarly for 1 week. Both gels were identical, but only one gel contained 2% diclofenac. Treatment order was randomized, and both the subject and tester were blinded. Pain and isometric wrist extension strength were measured using a visual analog pain scale (VAS) and a mounted manual muscle testing dynamometer, respectively, at the following time periods: just before application of the first gel, the last day of using the first gel, the last day of the washout week, and the last day of using the second gel. Analysis was performed using repeated measures analysis of variance.

RESULTS: When subjects used diclofenac PLO, pain was significantly less than that during the pretreatment, washout, and placebo PLO periods (mean VAS: diclofenac PLO, 2.1; pretreatment, 3.5; washout, 3.4; placebo PLO, 3.6). Average wrist extension strength was significantly greater when subjects used diclofenac PLO (8.4 kg) than it was before treatment (5.9 kg). One subject developed a local rash while using diclofenac PLO.

CONCLUSION: Topical 2% diclofenac in PLO appears to provide effective short-term reduction in elbow pain and wrist extensor weakness associated with chronic lateral epicondylitis.