June 19, 2012 — The osteoarthritis product Limbrel (flavocoxid) has been linked to four cases of liver damage, according to a report published in the Archives of Internal Medicine. Limbrel is a “medical food” available only by prescription, and because it is an “all natural” product containing green tea extracts, consumers may believe that it is both safe and effective.
In reality, because Limbrel is a “medical food,” it has never been reviewed by the Food and Drug Administration (FDA) for safety or effectiveness — and now there is evidence linking it to liver damage.
Similar to dietary supplements, “medical food” products do not need to provide the FDA with any evidence regarding safety or effectiveness before they can be sold in the U.S. Experts are concerned that many untested supplements could cause liver damage, which is why they began a study of nearly 900 people who are thought to have liver damage caused by a supplement or medication. Four cases of liver damage were linked to Limbrel.
The four patients taking Limbrel developed symptoms of liver damage within three months of starting the product, and all the cases resolved within 12 weeks after Limbrel was discontinued. The patients had symptoms including abdominal pain, jaundice (yellow discoloration of the skin and/or eyes), very itchy skin, high fever, and more.
The researchers cannot be absolutely sure that Limbrel caused the symptoms, but lead researcher Dr. Naga Chalasani says at least three cases were “highly likely” to have been caused by the product.
Furthermore, the researchers do not know exactly how Limbrel could have caused liver damage. They suspect that it has something to do with the plant compounds in the product. Limbrel contains high concentrations of plant compounds called flavinoids, including green tea extracts called catechins, which have been linked to liver toxicity.
The researchers are concerned that patients or doctors might choose Limbrel because it is plant-based, and “all natural,” falsely believing that “all natural” products are always safe and effective.
Osteoarthritis sufferers might choose Limbrel because there are very few safe and effective drug treatments for moderate or severe osteoarthritis. Experts recommend that people with moderate cases should take painkillers and anti-inflammatory drugs called NSAIDs (such as naproxen, ibuprofen, Celebrex, or other drugs). However, these drugs can increase the risk of stomach ulcers, gastrointestinal disorders, and heart attack. Another option is a cortisone shot in the joint, but this provides only temporary relief of symptoms.
The researchers recommend that patients should be discouraged from using Limbrel. Current Limbrel patients should be warned about the possible risk of liver damage, and monitored for signs of serious liver injury.