STUDY: Topical better then Oral

JOURNAL: J Rheumatol 2003;30:523-528.

AUTHORS: Dr. Cohen

ABSTRACT: A topical glucosamine/chondroitin sulfate cream containing camphor and peppermint oil provides fast and effective relief of pain from osteoarthritis (OA) of the knee.

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COMMENTARY: "These results support the growing volume of evidence that glucosamine and chondroitin sulfate are active agents against the pain from OA of the knee, and further suggest that these agents are effective when applied topically," Dr. Marc Cohen and colleagues write.

They randomized 63 patients with OA knee pain unrelieved by other agents to topical glucosamine/chondroitin cream, marketed in the US as Jointflex, or placebo. Patients were instructed to apply the creams as needed for 8 weeks. Average usage was 2.5 applications per day.

A reduction in pain was evident in the active treatment group after 1 day and "clinically significant" improvement" was seen at both 4 and 8 weeks. After 4 weeks, the difference between active and placebo groups in the mean reduction in pain from baseline as assessed by Visual Analog Scale (VAS) was 1.2 (p = 0.03) increasing to 1.8 after 8 weeks (p = 0.002).

In studies of oral glucosamine and chondroitin, effective pain relief is reported only after some weeks of treatment. In this study, they observed a noticeable effect after a single day of use. They were also surprised that the pain relief observed by the topical treatment continually improved over time.

There are theoretical reasons why topical application may be preferable to oral delivery of glucosamine and chondroitin. "Glucosamine is rapidly absorbed from the gastrointestinal tract when taken orally yet it is subject to rapid degradation by the liver and uptake into non-joint tissues," he explained. "Chondroitin on the other hand is poorly absorbed through the gastrointestinal tract. Topical application therefore has the potential to avoid these problems and deliver these substances directly to the painful joint."

Topical application of glucosamine and chondroitin may also modify the underlying disease process, he said, noting that "this has been demonstrated with oral glucosamine."