A randomized, double-blind, placebo-controlled trial of glucosamine sulphate as an analgesic in osteoarthritis of the knee

Objectives. A randomized, placebo-controlled, double-blind trial of the relative effectiveness of glucosamine sulphate and placebo in managing pain in osteoarthritis (OA) of the knee. Methods. Eighty patients with OA of the knee were recruited from a rheumatology out-patient clinic and received either glucosamine sulphate 1500 mg daily for 6 months or dummy placebo. The primary outcome measure was patients' global assessment of pain in the affected knee. Results. Area under the curve analysis for the primary outcome measure showed no difference between placebo and glucosamine [mean difference 0.15 min. 95%, confidence interval (CI) - 8.78 to 9.07]. The placebo response was 33%. There was a statistically significant difference between groups in knee flexion (mean difference 13, 95% CI - 23.13 to - 1.97) but this difference was small and could have been due to measurement error. Conclusions. As a symptom modifier in OA patients with a wide range of pain severities, glucosamine sulphate was no more effective than placebo.