Objective: Glucosamine, classified as a slow-acting drug in osteoarthritis (SADOA), is an efficacious chondroprotective agent. Methylsulfonylmethane (MSM), the isoxidised form of dimethyl-sulfoxide (DSMO), is an effective natural analgesic and anti-inflammatory agent. The aim of this study was to compare the efficacy and safety of oral glucosamine (Glu), methylsulfonylmethane (MSM), their combination and placebo in osteoarthritis of the knee.
Patients and design: A total of 118 patients of either sex with mild to moderate osteoarthritis were included in the study and randomised to receive either Glu 500mg, MSM 500mg, Glu and MSM or placebo capsules three times daily for 12 weeks. Patients were evaluated at 0 (before drug administration), 2, 4, 8 and 12 weeks post-treatment for efficacy and safety. The efficacy parameters studied were the pain index, the swelling index, visual analogue scale pain intensity, 15m walking time, the Lequesne index, and consumption of rescue medicine.
Results: Glu, MSM and their combination significantly improved signs and symptoms of osteoarthritis compared with placebo. There was a statistically significant decrease in mean (+/- SD) pain index from 1.74 +/- 0.47 at baseline to 0.65 +/- 0.71 at week 12 with Glu (p < 0.001). MSM significantly decreased the mean pain index from 1.53 +/- 0.51 to 0.74 +/- 0.65, and combination treatment resulted in a more significant decrease in the mean pain index (1.7 +/- 0.47 to 0.36 +/- 0.33; p < 0.001). After 12 weeks, the mean swelling index significantly decreased with Glu and MSM, while the decrease in swelling index with combination therapy was greater (1.43 +/- 0.63 to 0.14 +/- 0.35; p < 0.05) after 12 weeks. The combination produced a statistically significant decrease in the Lequesne index. All treatments were well tolerated.
Conclusion: Glu, MSM and their combination produced an analgesic and anti-inflammatory effect in osteoarthritis. Combination therapy showed better efficacy in reducing pain and swelling and in improving the functional ability of joints than the individual agents. All the treatments were well tolerated. The onset of analgesic and anti-inflammatory activity was found to be more rapid with the combination than with Glu. It can be concluded that the combination of MSM with Glu provides better and more rapid improvement in patients with osteoarthritis.