Copper-salicylate gel for pain relief in osteoarthritis: a randomised controlled trial.
OBJECTIVE
To assess the efficacy and safety of a copper-salicylate gel in osteoarthritis of the hip and knee.


METHODS
Randomised, double-blind, placebo-controlled study.


METHODS
Rheumatology Clinic of St Vincent's Hospital, Sydney, New South Wales (a tertiary referral hospital), June 1993 to October 1994.


METHODS
116 patients with pain associated with osteoarthritis of the hip and/or knee (diagnosed by criteria of the European League against Rheumatism), drawn from patients attending the Clinic or self-referred after newspaper advertisements.


METHODS
Copper-salicylate or placebo gel (1.5 g) applied twice daily to the forearm for four weeks.


METHODS
Self-assessment of pain before the trial and after two and four weeks of treatment; patient and investigator assessments of efficacy; additional analgesia required; adverse reactions; and withdrawal rates.


RESULTS
Pain scores at rest and on movement decreased in both the copper-salicylate and placebo groups by 13%-20%. There was no significant difference between the two groups for decrease in pain score, patient and investigator efficacy ratings, number of patients requiring paracetamol for extra analgesia (active, 77%; placebo, 71%) and average dose of paracetamol (active, 555 mg/day; placebo, 600 mg/day). Significantly more patients in the copper-salicylate group reported adverse reactions (83% versus 52% of the placebo group), most commonly skin reactions, and withdrew from the trial because of these reactions (17% versus 1.7% of the placebo group).


CONCLUSIONS
Copper-salicylate gel applied to the forearm was no better than placebo gel as pain relief for patients with osteoarthritis of the hip or knee, but produced significantly more skin rashes.
Shackel
N A
NA
Department of Clinical Pharmacology and Toxicology, St Vincent's Hospital, Sydney, NSW.
Day
R O
RO
Kellett
B
B
Brooks
P M
PM
D000279:Administration, Cutaneous; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage* / Q000009:adverse effects; D003300:Copper / Q000008:administration & dosage* / Q000009:adverse effects; D004311:Double-Blind Method; D005260:Female; D005782:Gels; D006801:Humans; D007719:Knee Joint; D008297:Male; D008875:Middle Aged; D009942:Organometallic Compounds / Q000008:administration & dosage* / Q000009:adverse effects; D010003:Osteoarthritis / Q000188:drug therapy*; D015207:Osteoarthritis, Hip / Q000188:drug therapy; D010147:Pain Measurement; D012459:Salicylates / Q000008:administration & dosage* / Q000009:adverse effects
D000894:Anti-Inflammatory Agents, Non-Steroidal; D005782:Gels; D009942:Organometallic Compounds; D012459:Salicylates; C025564:copper salicylate complex; D003300:Copper