Systematic review of efficacy of topical rubefacients containing salicylates for the treatment of acute and chronic pain.
OBJECTIVE
To determine the efficacy and safety of topical rubefacients containing salicylates in acute and chronic pain.


METHODS
Electronic databases and manufacturers of salicylates.


METHODS
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.


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


RESULTS
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.
Mason
Lorna
L
Pain Research and Nuffield Department of Anaesthetics, University of Oxford, Oxford Radcliffe Hospital, Headington, Oxford OX3 7LJ.
Moore
R Andrew
RA
Edwards
Jayne E
JE
McQuay
Henry J
HJ
Derry
Sheena
S
Wiffen
Philip J
PJ
D000208:Acute Disease; D000287:Administration, Topical; D000700:Analgesics / Q000008:administration & dosage*; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage*; D002908:Chronic Disease; D004311:Double-Blind Method; D006801:Humans; D007509:Irritants / Q000008:administration & dosage*; D010146:Pain / Q000188:drug therapy*; D016032:Randomized Controlled Trials as Topic; D012459:Salicylates / Q000008:administration & dosage*; D016896:Treatment Outcome
D000700:Analgesics; D000894:Anti-Inflammatory Agents, Non-Steroidal; D007509:Irritants; D012459:Salicylates