Glucosamine & Chondroitin Sulfate
Glucosamine and chondroitin sulfate taken together are effective in treating moderate to severe knee pain due to OA in some patients. These substances can help reduce swelling and tenderness, as well as improve mobility and function by decreasing enzymatic cartilage degradation. If you decide to take this therapy, it is important not to discontinue them too soon and use them as directed on package inserts. At least three months of continuous use is necessary before the full effect is realized. Dosing at a dose of 1500mg of Glucosamine and 1200mg of Chondroitin sulfate per day is necessary and is supported by the GAIT trial funded by the NIH (National Institutes of Health).
What is osteoarthritis?
More than 20 million adults in the United States live with osteoarthritis–the most common type of arthritis. Osteoarthritis, also called degenerative joint disease, is caused by the breakdown of cartilage, which is the connective tissue that cushions the ends of bones within the joint. Osteoarthritis is characterized by pain, joint damage, and limited motion. The disease generally occurs late in life, and most commonly affects the hands and large weight-bearing joints, such as the knees. Age, female gender, and obesity are risk factors for this condition.
© National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
What is the Glucosamine/chondroitin Arthritis Intervention Trial (GAIT)?
The Efficacy of Glucosamine and Chondroitin Sulfate in Patients with Painful Knee Osteoarthritis (OA): The Glucosamine/chondroitin Arthritis Intervention Trial (GAIT). GAIT is the first, large-scale, multicenter clinical trial in the United States to test the effects of the dietary supplements glucosamine hydrochloride (glucosamine) and sodium chondroitin sulfate (chondroitin sulfate) for treatment of knee osteoarthritis. The study tested whether glucosamine and chondroitin sulfate used separately or in combination reduced pain in participants with knee osteoarthritis. In the study these substances were required to meet pharmaceutical standards as GAIT was conducted under an Investigational New Drug application.
What are glucosamine and chondroitin sulfate?
Glucosamine and chondroitin sulfate are natural substances found in and around the cells of cartilage. Glucosamine is an amino sugar that the body produces and distributes in cartilage and other connective tissue, and chondroitin sulfate is a complex carbohydrate that helps cartilage retain water. In the United States, glucosamine and chondroitin sulfate are sold as dietary supplements, which are regulated as foods rather than drugs. Supplements sold over-the-counter are usually made from synthetic or animal products. Although glucosamine and chondroitin sulfate are natural substances, they can cause side effects such as headaches, stomach upset, nausea, vomiting, and skin reactions. These supplements can interact with other medications, so keep your doctor informed about your use of them.
What were the key results of the GAIT study?
Researchers found that:
Participants taking the positive control, celecoxib, experienced statistically significant pain relief versus placebo–about 70 percent of those taking celecoxib had a 20 percent or greater reduction in pain versus about 60 percent for placebo.
Overall, there were no significant differences between the other treatments tested and placebo.
For a subset of participants with moderate-to-severe pain, glucosamine combined with chondroitin sulfate provided statistically significant pain relief compared to placebo–about 79 percent had a 20 percent or greater reduction in pain versus about 54 percent for placebo. According to the researchers, because of the small size of this subgroup these findings should be considered preliminary and need to be confirmed in further studies.
For participants in the mild pain subset, glucosamine and chondroitin sulfate together or alone did not provide statistically significant pain relief.
What is celecoxib?
Celecoxib (brand name Celebrex) is a type of nonsteroidal anti-inflammatory drug (NSAID), called a COX-2 inhibitor. Like traditional NSAIDs, celecoxib blocks the COX-2 enzyme in the body that stimulates inflammation. Unlike traditional NSAIDs, however, celecoxib does not block the action of COX-1 enzyme, which is known to protect the stomach lining. As a result, celecoxib reduces joint pain and inflammation with reduced risk of gastrointestinal ulceration and bleeding. Recent reports have linked possible cardiovascular side effects to COX-2 inhibitors. Although GAIT was not designed to study the safety of celecoxib, participants were monitored for adverse events and no increase in such side effects was observed.
What doses were used for the various treatments?
The doses used in GAIT were based on the doses seen in the prevailing scientific literature.
Glucosamine alone: 1500 mg daily given as 500 mg three times a day
Chondroitin sulfate alone: 1200 mg daily given as 400 mg three times a day
Glucosamine plus chondroitin sulfate combined: same doses-1500 mg and 1200 mg daily
Celecoxib: 200 mg daily
Acetaminophen: participants were allowed to take up to 4000 mg (500 mg tablets) per day to control pain, except for the 24 hours before pain was assessed.
Recommended Brands?
Please note that pharmaceutical grade Glucosamine and Chondroitin sulfate is not regulated and therefore may not be obtainable. The following are known reputable brands.
- Cosamin DS
- CVS (Generic)
- Sam’s Club