Time to significant pain reduction following DETP application vs placebo for acute soft tissue injuries

Abstract

Objective:

Nonsteroidal anti-inflammatory drugs (NSAIDs) provide fast and effective acute pain relief, but systemic administration has increased risk for some adverse reactions. The diclofenac epolamine 1.3% topical patch (DETP) is a topical NSAID with demonstrated safety and efficacy in treatment of acute pain from minor soft tissue injuries. Significant pain reduction has been observed in clinical trials within several hours following DETP application, suggesting rapid pain relief; however, this has not been extensively studied for topical NSAIDs in general. This retrospective post-hoc analysis examined time to onset of significant pain reduction after DETP application compared to a placebo patch for patients with mild-to-moderate acute ankle sprain, evaluating the primary efficacy endpoint from two nearly identical studies.

Research design and methods:

Data from two double-blind, randomized, parallel-group, placebo-controlled studies (N = 274) of safety and efficacy of the DETP applied once daily for 7 days for acute ankle sprain were evaluated post-hoc using statistical modeling to estimate time to onset of significant pain reduction following DETP application.

Main outcome measures:

Pain on active movement on a 100 mm Visual Analog Scale (VAS) recorded in patient diaries; physician- and patient-assessed tolerability; and adverse events.

Results:

DETP treatment resulted in significant pain reduction within approximately 3 hours compared to placebo. Within-treatment post-hoc analysis based on a statistical model suggested significant pain reduction occurred as early as 1.27 hours for the DETP group. The study may have been limited by the retrospective nature of the analyses. In both studies, the DETP was well tolerated with few adverse events, limited primarily to application site skin reactions.

Conclusion:

The DETP is an effective treatment for acute minor soft tissue injury, providing pain relief as rapidly as 1.27 hours post-treatment. Statistical modeling may be useful in estimating time to onset of pain relief for comparison of topical and oral NSAIDs.

Key words::

• Acute injury
• Diclofenac
• Soft tissue injury
• Topical
• Visual Analog Scale

Transparency

Declaration of funding

The studies included in this manuscript were co-sponsored by Institut Biochimique SA (Pambio-Noranco, Switzerland) and Laboratoires Genévrier (Sophia Antipolis, France). The post-hoc statistical modeling, writing, and editorial support were funded by King Pharmaceuticals Inc., Bridgewater, NJ, USA.

Declaration of financial/other relationships

J.Y. and M.M. have disclosed that they were employees of Alpharma Pharmaceuticals, LLC, a wholly owned subsidiary of King Pharmaceuticals, Inc., at the time of this work. S.R. has disclosed that he is an employee of Institut Biochimique SA, which sponsored the DETP studies described herein. J.B. has disclosed that, at the time of the study, she was an employee of MMS Holdings, Inc., which received funding for the data analyses and drafting of the manuscript. J.S. has disclosed that he is an employee of MMS Holdings.

Some peer reviewers receive honoraria from CMRO for their review work. The peer reviewers of this paper have disclosed that they have no relevant financial relationships.

Acknowledgments

The authors gratefully acknowledge Drs. Joussellin and Saillant, the principle investigators of the studies described and analyzed herein, and Drs. Martin Stillman and Paul Cavanaugh for critical review of the manuscript. The authors also acknowledge MMS Holdings Inc. for assistance with preparation of this publication.