June 19, 2012 — A new study published in the Annals of Internal Medicine has linked the “medical food” product Limbrel (flavocoxid) to at least four cases of serious liver damage, which healed within weeks after discontinuation. Limbrel is an “all natural” product sold only by prescription as a treatment for osteoarthritis, which occurs when cartilage breaks down around the joints.
A “medical food” is more similar to a dietary supplement than a prescription drug — while drugs must undergo stringent tests for safety and effectiveness, dietary supplements and “medical foods” do not. Manufacturers are allowed to sell the products without proving to the Food and Drug Administration (FDA) that the product is safe or effective.
The report described four cases in which people taking Limbrel developed temporary liver damage, characterized by abdominal pain, jaundice (yellowing of the skin and eyes), itchy skin, fever, and other side effects. These symptoms resolved when the patients discontinued Limbrel.
The researchers caution that they cannot be sure that Limbrel caused the liver injury, but at least three cases were “highly likely” to have been caused by the product, according to the lead researcher, Dr. Naga Chalasani. All of the patients had symptoms of liver damage within three months of using Limbrel, and all the patients recovered within 12 weeks of discontinuing the product.
Limbrel contains a mixture of plant compounds called flavinoids, including catechins, which are an extract of green tea. High concentrations of catechins have been linked to liver toxicity. The researchers were concerned that people would choose Limbrel because it is an “all natural” product, falsely assuming that it is safe.
The researchers advised that people should be discouraged from using Limbrel or other dietary supplements to treat osteoarthritis. Furthermore, patients who are currently taking Limbrel should be monitored for signs of liver damage.
Unfortunately, there are few failsafe treatment options for people who have osteoarthritis. For moderate cases of osteoarthritis, painkillers and anti-inflammatory NSAIDs (naproxen, ibuprofen, Celebrex, etc.) could reduce symptoms of the disease. However, these drugs may increase the risk of heart attack, stomach ulcers, and gastrointestinal problems. Cortisone shots provide only temporary relief. There are limited treatment options that are both safe and effective for osteoarthritis, which is why some people might choose Limbrel, believing that an “all natural” product is safer than other treatments. Unfortunately, it may actually increase the risk of liver damage.