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
