WEDNESDAY, Jan. 11, 2012 (HealthDay News) -- There is little evidence to support the widespread use of herbal medicines to relieve the symptoms of osteoarthritis, according to a review of these products.
Osteoarthritis is a painful condition that involves damage to cartilage and other structures in and around the joints, particularly the fingers, knees and hips. It differs from rheumatoid arthritis, which is an immune-based disorder.
Devil's claw, cat's claw, ginger, nettle, rosehip, turmeric, willow bark, Indian frankincense and vegetable extracts of avocado or soybean oils are all among the herbal medicines traditionally used to treat osteoarthritis.
"Unfortunately, a large number of people suffer from osteoarthritis pain," said one expert, Dr. Robert Graham, an internist at Lenox Hill Hospital in New York City.
"Current pharmacological management is largely focused upon reduction of pain and of inflammation with the use of NSAIDs [painkillers] and Tylenol, offering only temporary pain relief at the expense of known adverse effects associated with NSAID use," he added. "Patients have and will continue to use herbal and dietary supplements with hopes of finding the 'cure' for osteoarthritis pain, many times without sharing this with a conventional medical professional."
However, few studies on the use of herbal medicines for osteoarthritis have been conducted, according to the authors of the review in the January issue of the journal Drug and Therapeutics Bulletin. Many of the studies that have been carried out had design flaws and limitations, included too few patients, or weren't long enough, according to a journal news release.
The available clinical trial evidence suggests that the vegetable extracts, Indian frankincense and rosehip may be effective and produce few unwanted side effects, but more "robust data are needed," according to the journal.
Evidence in favor of the use of other herbal medicine is at best equivocal or unconvincing, the review found.
"Use of herbal supplements comes up a lot in the treatment of joint pain," said Dr. Victor Khabie, chief of surgery and sports medicine at Northern Westchester Hospital Center, in Mount Kisco, N.Y. "I have never seen a study that has convinced me that its use is beneficial."
The journal also warned that herbal medicines can interfere with other medicinal products and prescription drugs. For example, extensive use of nettle can interfere with drugs used to treat diabetes, lower blood pressure and depress the central nervous system. Willow bark can cause digestive and kidney problems.
"Herbal medicines have traditionally been used for the relief of osteoarthritis symptoms. However, there is a lack of licensed herbal medicinal products on the market for such symptoms, and none specifically licensed for osteoarthritis," the journal concluded.
"Also the efficacy and safety of such products is generally under- researched and information on potentially significant herb-drug interactions is limited," the release added.
For his part, Graham said that some patients do seem to be helped by herbal remedies.
"In some cases patients may be able to lower or stop the use of NSAIDs and to avoid the adverse effects of NSAIDs," he said. "Unfortunately, the [review] authors did not review the popular dietary supplements glucosamine and chondroitin sulfate alone or in combination, which has been shown to be effective in a subgroup of patients with moderate-to-severe pain.
"Although prospective studies are needed, I do believe that their use should be discussed with [patients'] physicians and physicians should consider integrating some of the more promising and/or safest herbals and dietary supplements into their standard of practice -- their patients are already doing it," Graham said.
Khabie agreed that certain herbals might seem to work for some patients, although the reasons remain uncertain. "I do have patients who tell me that various supplements have relieved their joint pain, and it is unclear whether they are responding to a placebo effect," he said. "Some herbal supplements can act as blood thinners, which could complicate upcoming surgery, so I usually ask my patients to discontinue their use two weeks prior to their procedure."
Doctors treating patients with osteoarthritis should routinely ask them if they are taking any herbal products, the journal suggested.
The U.S. National Institute of Arthritis and Musculoskeletal and Skin Diseases has more about osteoarthritis.