Primary care

Systematic review of efficacy of topical rubefacients containing salicylates for the treatment of acute and chronic pain

BMJ 2004; 328 doi: 10.1136/bmj.38040.607141.EE (Published 22 April 2004)
Cite this as: BMJ 2004;328:995
  1. Lorna Mason, research associate1,
  2. R Andrew Moore, director of research (andrew.moore{at}pru.ox.ac.uk)1,
  3. Jayne E Edwards, senior researcher1,
  4. Henry J McQuay, professor of pain relief1,
  5. Sheena Derry, senior researcher1,
  6. Philip J Wiffen, coordinating editor, Cochrane Pain and Palliative Care Group1
  1. 1Pain Research and Nuffield Department of Anaesthetics, University of Oxford, Oxford Radcliffe Hospital, Headington, Oxford OX3 7LJ
  1. Correspondence to: R A Moore
  • Accepted 20 February 2004

Abstract

Objective To determine the efficacy and safety of topical rubefacients containing salicylates in acute and chronic pain.

Data sources Electronic databases and manufacturers of salicylates.

Study selection Randomised double blind trials comparing topical rubefacients with placebo or another active treatment, in adults with acute or chronic pain, and reporting dichotomous information, around a 50% reduction in pain, and analyses at one week for acute conditions and two weeks for chronic conditions.

Data extraction Relative benefit and number needed to treat, analysis of adverse events, and withdrawals.

Data synthesis Three double blind placebo controlled trials had information on 182 patients with acute conditions. Topical salicylate was significantly better than placebo (relative benefit 3.6, 95% confidence interval 2.4 to 5.6; number needed to treat 2.1, 1.7 to 2.8). Six double blind placebo controlled trials had information on 429 patients with chronic conditions. Topical salicylate was significantly better than placebo (relative benefit 1.5, 1.3 to 1.9; number needed to treat 5.3, 3.6 to 10.2), but larger, more valid studies were without significant effect. Local adverse events and withdrawals were generally rare in trials that reported them.

Conclusions Based on limited information, topically applied rubefacients containing salicylates may be efficacious in the treatment of acute pain. Trials of musculoskeletal and arthritic pain suggested moderate to poor efficacy. Adverse events were rare in studies of acute pain and poorly reported in those of chronic pain. Efficacy estimates for rubefacients are unreliable owing to a lack of good clinical trials.

Footnotes

  • Contributors LM was involved with planning, searching, reading the papers, quality scoring, data extraction, analysis, and writing. RAM was involved with planning, reading the papers, quality scoring, analysis, and writing. JE was involved with reading the papers, quality scoring, data extraction and analysis, and commenting on the text. HJM was involved with planning and commenting on the text. SD was involved with analysis and checking and revising. PJW was involved with planning and commenting on the text. RAM and HJM will act as guarantors for the paper. The guarantors accept full responsibility for the conduct of the study, had access to the data, and controlled the decision to publish.

  • Funding The work was supported by research funds from the Oxford Pain Relief Trust

  • Competing interests RAM and HJM have consulted for various pharmaceutical companies. RAM, HJM, and JE have received lecture fees from pharmaceutical companies related to analgesics and other healthcare interventions. All authors have received research support from charities, government, and industry sources at various times, but no such support was received for this work.

  • Ethical approval Not required.

  • Accepted 20 February 2004

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