Original Research
Randomized Double-Blind Trial Comparing Oral Paracetamol and Oral Nonsteroidal Antiinflammatory Drugs for Treating Pain After Musculoskeletal Injury

https://doi.org/10.1016/j.annemergmed.2005.01.023Get rights and content

Study objective

We investigate the efficacy and safety of oral paracetamol compared with oral nonsteroidal antiinflammatory drugs or combination therapy in relieving pain after blunt limb injury in an emergency department (ED).

Methods

This was a double-blind, randomized, controlled study in an ED of a university hospital in the New Territories of Hong Kong. Three hundred adult patients with painful isolated limb injuries were enrolled. Primary outcome measures were pain relief at rest and with limb movement, adverse events, and patient satisfaction.

Results

There was no statistical difference in the mean reduction in pain score between any of the combinations at any point, although combination therapy was the first to reach a clinically significant reduction in pain score (<13 mm), and diclofenac-paracetamol combinations consistently produced a greater reduction in mean pain score than either nonsteroidal antiinflammatory drugs or paracetamol alone. All combinations appeared to be safe, although more patients receiving diclofenac-paracetamol combination complained of abdominal pain. The median patient satisfaction scores were poor.

Conclusion

In the doses, frequencies, and routes of administration used for this study, any analgesic benefit of oral paracetamol–nonsteroidal antiinflammatory drug combinations over single nonsteroidal antiinflammatory drugs or paracetamol treatment is small and of doubtful clinical significance. Nonsteroidal antiinflammatory drugs, paracetamol, and diclofenac-paracetamol combinations appeared equally safe in the management of musculoskeletal pain.

Introduction

Nonsteroidal antiinflammatory drugs are widely used. In the western world, it is estimated that almost 10% of the population have used a nonsteroidal antiinflammatory drug at some time and that an average of 11 to 36 people per 1,000 population consume a nonsteroidal antiinflammatory drug each day.1, 2 These drugs have antiinflammatory, analgesic, antipyretic, and antithrombotic effects3 yet have no known effect on disease processes itself. They are currently indicated for many acute and chronic musculoskeletal problems of mild to moderate pain intensity.

A recent Cochrane review of randomized clinical trials found little evidence of any difference in efficacy or dose effect between different nonsteroidal antiinflammatory drugs in the management of rheumatoid arthritis, osteoarthritis, or acute musculoskeletal syndrome.4 No large, double-blind, randomized, controlled trial with more than 100 participants has compared paracetamol with nonsteroidal antiinflammatory drugs in the treatment of pain in acute musculoskeletal syndromes.4 Our study aimed to recruit a sufficient number of subjects in order to demonstrate the efficacy of nonsteroidal antiinflammatory drugs versus paracetamol. Readers would then have a better guide in choosing analgesics in a more cost-effective manner.

The aim of this study is to compare the analgesic efficacy and safety of oral nonsteroidal antiinflammatory drugs with oral paracetamol or diclofenac-paracetamol combination therapy in the management of pain after acute musculoskeletal syndrome in an emergency department (ED) setting. We hypothesized that paracetamol would be as efficacious as nonsteroidal antiinflammatory drugs or combination therapy in the management of acute pain and would be associated with fewer adverse events. Participants were randomized into 4 groups, and each received combinations of analgesics or placebo. Pain scores were measured in 2 stages: acutely in the ED (stage 1) and for 3 consecutive days after discharge (stage 2). The occurrence and severity of adverse effect were also recorded at each stage.

Section snippets

Study Design

This was a randomized, double-blind, controlled trial comparing 3 drugs, namely, paracetamol, indomethacin, and diclofenac potassium. After checking that participants satisfied the predetermined inclusion and exclusion criteria, subjects were randomized into 4 groups. Each group received 2 study drugs (X and Y). Drug X could be either paracetamol or paracetamol-like placebo. Drug Y could be indomethacin, indomethacin-like placebo, or diclofenac potassium. Pain scores were recorded by a

Results

Between January 7, 2002, and June 24, 2003, 300 patients attended the ED between 9 am and 5 pm, Monday to Friday, with acute painful musculoskeletal injuries were allocated to receive blinded analgesia (Figure 1). Baseline characteristics of the participants in the 4 groups were similar (Table 1). Because of the triage and consenting processes involved in the study, 35 to 40 minutes passed between arrival at the department and initiation of analgesia. Initial mean pain scores at rest were mild

Limitations

The strengths of the study lie in its randomized, controlled design; its simple, practical, safe method of delivery of analgesia; and in its attempt to reflect the real world as far as reasonably possible. The doses of nonsteroidal antiinflammatory drugs used in this study reflected normal prescribing practice in our department. We have sought to reflect our real world, but these doses may be lower than those used in other health care settings. It is possible that higher doses produce a greater

Discussion

These results show that at the doses, frequencies, and routes of administration used in this study, oral paracetamol appears to be as effective as oral indomethacin, oral diclofenac, and oral diclofenac-paracetamol combination in the management of pain in musculoskeletal syndrome of minor to moderate severity. At the doses, frequencies, and durations used in the treatment of these participants, there were no severe adverse events and no significant differences in the proportion of patients with

References (16)

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Supervising editor: Knox H. Todd, MD, MPH

Author contributions: TR had the idea for the study, obtained approval, and has overseen the entire planning, execution, analysis, and preparation of manuscript. He is guarantor of the work. WKW and SYM participated in the planning, execution, and analysis. PL and TR prepared the statistical analysis. TR wrote the first draft of the paper, and all authors have contributed to the final version. TR takes responsibility for the paper as a whole.

Funding and support: The authors report this study did not receive any outside funding or support.

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