Time to stop glucosamine and chondroitin for knee OA?
Prior studies provided conflicting results regarding the efficacy of these medications. This study offers evidence for discontinuing them.
PRACTICE CHANGER
Tell patients with moderately severe osteoarthritis to stop taking their glucosamine and chondroitin as it is less effective than placebo.1
STRENGTH OF RECOMMENDATION
B: Based on single, good-quality randomized controlled trial.
Roman-Blas JA, Castañeda S, Sánchez-Pernaute O, et al. Combined treatment with chondroitin sulfate and glucosamine sulfate shows no superiority over placebo for reduction of joint pain and functional impairment in patients with knee osteoarthritis: a six-month multicenter, randomized, double-blind, placebo-controlled clinical trial. Arthritis Rheumatol. 2017;69:77-85.
Baseline global pain scores were 62 mm in both groups. Acetaminophen, up to 3 g/d, was the only allowed rescue medication. Clinic visits occurred at 4, 12, and 24 weeks. A statistically significant difference between groups was defined as P<.03.1
Results. In the intention-to-treat analysis at 6 months, patients in the placebo group had a greater reduction in pain than the CS/GC group (-20 mm vs -12 mm; P=.029). No other difference was noted between the placebo and CS/GS groups in the total or subscales of the WOMAC index, and no difference was noted in use of acetaminophen. More patients in the placebo group had at least a 50% improvement in pain or function compared with the CS/GS group (47.4% vs 27.5%; P=.01).
In the CS/GS group, 31% did not complete the 6-month treatment period, compared with 18% in the placebo group. More patients dropped out because of adverse effects (diarrhea, upper abdominal pain, and constipation) in the CS/GS group than the placebo group (33 vs 19; P=.018).1
WHAT’S NEW
A pharma-sponsored study finds treatment ineffective
The effectiveness of CS/GS for the treatment of knee OA has been in question for years, but this RCT is the first trial sponsored by a pharmaceutical company to evaluate CS/GS efficacy. This trial found evidence of a lack of efficacy. In patients with more severe OA of the knee, placebo was more effective than CS/GS, and CS/GS had significantly more adverse events. Therefore, it may be time to advise patients to stop taking their CS/GS supplement.
CAVEATS
Cannot generalize findings to CS or GS alone, or different dosages
The study compared only one medication dosing regimen using a combination of CS and GS. Whether either agent alone or different dosing would lead to the same outcome is unknown.
Continue to: CHALLENGES TO IMPLEMENTATION
