Topical nonsteroidal anti-inflammatory drugs (NSAIDs) may be safe and effective for acute musculoskeletal conditions in adults, according to the results of a systematic review reported online June 16 in the Cochrane Database of Systematic Reviews.
"Use of topical NSAIDs to treat acute musculoskeletal conditions is widely accepted in some parts of the world, but not in others," write Thomas Massey, from the University of Oxford, Oxford, United Kingdom, and colleagues. "Their main attraction is their potential to provide pain relief without associated systemic adverse events."
The goal of the study was to evaluate the evidence from randomized, double-blind, controlled trials of the efficacy and safety of topically applied NSAIDs for relief of acute pain. The investigators searched MEDLINE, EMBASE, The Cochrane Library, and their own in-house database to December 2009. To identify unpublished studies, they also asked other investigators and searched online clinical trial registers and manufacturers' Web sites.
Inclusion criteria were active or placebo (inert carrier)–controlled trials in adults with strains, sprains, or sports or overuse-type injuries causing acute pain, with ten or more participants in each treatment group, and treatment application at least once daily.
Two reviewers independently examined trial quality and validity and extracted data from 47 included studies enrolling a total of 3455 participants for overall efficacy analysis. Most of the identified studies compared topical NSAID gel, spray, or cream vs a similar placebo, Relative risk and numbers needed to treat or number needed to harm for topical NSAIDs vs placebo or other active treatment were determined from numbers of participants achieving each outcome.
The number needed to treat for clinical success, defined as 50% pain relief, for all topical NSAIDs combined vs placebo was 4.5 (95% confidence interval [CI], 3.9 - 5.3) for treatment periods of 6 to 14 days. Although topical diclofenac, ibuprofen, ketoprofen, and piroxicam were similarly effective, indomethacin and benzydamine were not significantly more effective than placebo.
There were very few systemic adverse events or adverse events causing study withdrawals, and local skin reactions were usually mild, self-limited, and not different from those seen with placebo.
"There were insufficient data to reliably compare individual topical NSAIDs with each other or the same oral NSAID," the study authors write. "Topical NSAIDs can provide good levels of pain relief, without the systemic adverse events associated with oral NSAIDs, when used to treat acute musculoskeletal conditions."
Limitations of this review include those inherent in the selected studies, such as small sample size, varying study designs and conditions, and lack of methodologic details.
"Topical NSAIDs can provide good levels of pain relief in acute conditions such as sprains, strains and overuse injuries, probably similar to that provided by oral NSAIDs," the study authors conclude. "There appears to be little difference in analgesic efficacy between topical diclofenac, ibuprofen, ketoprofen and piroxicam, but indomethacin is less effective, and benzydamine is no better than placebo. Topical NSAIDs are not associated with an increased incidence of local skin reactions compared with placebo, and do not cause systemic (mainly gastrointestinal) problems commonly seen with oral NSAIDs, making them particularly useful for individuals unable to tolerate oral administration, or for whom it is contraindicated."
Support for this review was from Pain Research Funds, the NHS Cochrane Collaboration Programme Grant Scheme, and the NIHR Biomedical Research Centre Programme. Some of the study authors have disclosed various financial relationships with charities, government and industry sources, and/or pharmaceutical companies.
Cochrane Database Syst Rev. Published online June 16, 2010. Abstract
Laurie Barclay, MD • Medscape Medical News © 201 Medscape, LLC