The treatment of osteoarthritis, to date, is essentially palliative.
Osteoarthritis is a degenerative disease where the articular cartilage- the gristle that caps the ends of long bones wears away. More than 20 million Americans suffer from osteoarthritis, making it the most common form of arthritis.
While the therapeutic approach varies from practitioner to practitioner, the general thrust is similar.
Patients are treated with analgesics or non-steroidal anti-inflammatory drugs, physical therapy, injections of glucocorticoids, injections of hyaluronic acid ("rooster comb") lubricants, and then have surgery.
In patients with relatively mild disease, physicians may also prescribe topical agents.
Many doctors feel that topical non-steroidal drugs may be safer to use than oral anti-inflammatory drugs.
A recent study assessed the efficacy and safety of diclofenac gel in the treatment of osteoarthritis of the knee in people aged 65 and older. This was actually a compilation of data from three large randomized studies that enrolled a total of 538 patients. Four hundred and thirty three of the volunteers had associated medical problems such as diabetes, high blood pressure, and cardiovascular disease. The data was reported by Dr. H. Richard Barthel and colleagues at the annual meeting of the American Medical Directors Association.
The patients applied either the topical diclofenac gel in a dose of four grams per day or placebo.
The time frame evaluated was 12 weeks of therapy.
Analysis of the data showed that 56 per cent of the patients who received diclofenac gel had side effects compared with 44 per cent of the placebo group.
One patient, an 80-year old woman, developed a blood clot in the leg and a subsequent pulmonary embolism that was felt to possibly be related to drug therapy.
Non-steroidal anti-inflammatory drugs are associated with an increased incidence of cardiovascular disease, particularly in older individuals with an underlying history of hypertension, diabetes, and other cardiovascular disease.
The systemic absorption of topical diclofenac gel is forty times less than the absorption of oral diclofenac according to Dr. Roy Altman, professor of medicine at the University of California, Los Angeles. While topical agents may reduce the risk of these problems compared with oral preparations, they do not eliminate them totally.
Also found in the analysis was a much higher rate of skin reactions related to the diclofenac gel. Reactions at the site of application occurred in 8.8 per cent of diclofenac gel patients and only 1.1 per cent of placebo treated patients.
Adverse cardiovascular problems occurred in 2.6 per cent of the diclofenac patients versus 1.1 per cent of placebo treated patients.
Besides the currently available Volteren gel, another recent FDA approved topical preparation is Pennsaid, another diclofenac-based rub.
Another set of studies on Pennsaid, another topical diclofenac preparation, that uses DMSO for penetration, showed efficacy in at least two more studies presented at the American College of Rheumatology meetings in Atlanta, Georgia, from November 7 to November 11. Side effects were generally similar to that of the gel preparation.
In addition, Lidoderm patches were demonstrated to be effective for pain relief in one study of knee arthritis presented at the same meeting. Side effects were few.
While studies like this are interesting, they show the relative inadequacy of current treatment available for osteoarthritis. Pain relief is available but cartilage restoration is still not generally available. Recent data on mesenchymal stem cells does look promising as a method for restoring articular cartilage.
