A 65-year-old man with moderately severe osteoarthritis (OA) of the knee presents to your office for his annual exam. During the medication review, the patient mentions he is using glucosamine and chondroitin for his knee pain, which was recommended by a family member. Should you tell the patient to continue taking the medication?
Knee OA is a common condition in the United States, affecting an estimated 12% of adults ages 60 and older and 16% of those ages 70 and older.2 The primary goals of OA therapy are to minimize pain and improve function. The American Academy of Orthopedic Surgeons (AAOS) and the American College of Rheumatology (ACR) agree that firstline treatment recommendations include aerobic exercise, resistance training, and weight loss.
Initial pharmacologic therapies include full-strength acetaminophen or oral/topical NSAIDs; the latter are also used if pain is unresponsive to acetaminophen.3,4 If initial therapy is inadequate to control pain, tramadol, other opioids, duloxetine, or intra-articular injections with corticosteroids or hyaluronate are alternatives.3,4 Total knee replacement may be indicated in moderate or severe knee OA with radiographic evidence.5 Vitamin D, lateral wedge insoles, and antioxidants are not currently recommended.6
Prior studies evaluating glucosamine and/or chondroitin have provided conflicting results regarding evidence on pain reduction, function, and quality of life. Therefore, guidelines on OA management do not recommend their use (AAOS, strong; ACR, conditional).3,4 However, consumption remains high, with 6.5 million US adults reporting use of glucosamine and/or chondroitin in the prior 30 days.7
A 2015 systematic review of 43 randomized trials evaluating oral chondroitin sulfate for OA of varying severity suggested there may be a significant decrease in short-term and long-term pain with doses ≥ 800 mg/d compared with placebo (level of evidence, low; risk for bias, high).8 However, no significant difference was noted in short- or long-term function, and the trials were highly heterogeneous.
Studies included in the 2015 systematic review found that glucosamine plus chondroitin did not have a significant effect on short- or long-term pain or physical function compared with placebo. Although glucosamine plus chondroitin led to significantly decreased pain compared with other medication, sensitivity analyses conducted for larger studies (N > 200) with adequate methods of blinding and allocation concealment found no difference in pain.8 There was no statistically significant difference in adverse events for glucosamine plus chondroitin vs placebo, based on data from three studies included in the review.8
This RCT from Roman-Blas et al evaluated chondroitin and glucosamine vs placebo in patients with more severe OA. The study was supported by Tedec-Meiji Farma (Madrid), maker of the combination of chondroitin plus glucosamine used in the study.1
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