Short-Term Efficacy of Rofecoxib and Diclofenac in Acute Shoulder Pain: A Placebo-Controlled Randomized Trial

Objectives: To evaluate the short-term symptomatic efficacy of rofecoxib and diclofenac versus placebo in acute episodes of shoulder pain. Design: Randomized controlled trial of 7 days. Setting: Rheumatologists and/or general practitioners totaling 47. Participants: Acute shoulder pain. Interventions: Rofecoxib 50 mg once daily, diclofenac 50 mg three times daily, and placebo. Outcome measures: Pain, functional impairment, patient's global assessment of his/her disease activity, and local steroid injection requirement for persistent pain. The primary variable was the Kaplan-Meier estimates of the percentage of patients at day 7 fulfilling the definition of success (improvement in pain intensity and a low pain level sustained to the end of the 7 days of the study; log-rank test). Results: There was no difference in the baseline characteristics between the three groups (rofecoxib n = 88, placebo n = 94, and diclofenac n = 89). At day 7, the Kaplan-Meier estimates of successful patients was higher in the treatment groups than in the placebo (54%, 56%, and 38% in the diclofenac, rofecoxib, and placebo groups respectively, p = 0.0070 and p = 0.0239 for placebo versus rofecoxib and diclofenac, respectively). During the 7 days of the study, there was a statistically significant difference between placebo and both active arms (rofecoxib and diclofenac) in all the evaluated outcome measures A local steroid injection had to be performed in 33 (35%) and 19 (22%) patients in the placebo and rofecoxib group respectively. Number needed to treat to avoid such rescue therapy was 7 patients (95% confidence interval 5–15). Conclusion: This study highlights the methodological aspects of clinical trials, e.g., eligibility criteria and outcome measures, in acute painful conditions. The data also establish that diclofenac and rofecoxib are effective therapies for the management of acute painful shoulder and that they reduce the requirement for local steroid injection. Trial Registration: ClinicalTrials.gov NCT00140933 : Background: Shoulder pain is a very common complaint that presents in primary care, and there are many different possible causes. Acute pain would normally be managed with nonsteroidal anti-inflammatory drugs (NSAIDs), supplemented with steroid injections (which are often reserved for the treatment of severe or persistent pain). One NSAID, diclofenac, is used frequently for this condition, but other NSAIDs might also be effective. A subgroup of NSAIDs called the Cox-2 selective inhibitors specifically inhibit one particular enzyme (cyclo-oxygenase, shortened to Cox-2) which is involved in inflammation and pain. These drugs are thought to be less likely to cause stomach irritation than other NSAIDs. Therefore the researchers in this study carried out a short-term, three-way clinical trial comparing diclofenac with one particular Cox-2 inhibitor, rofecoxib, and placebo in patients with acute shoulder pain. However, rofecoxib was withdrawn from the market in September 2004 because of evidence that use of the drug was associated with an increased risk of heart attacks and strokes, and controversy remains regarding the risk of such events among users of other Cox-2 inhibitors.