Even when they took into account the severity of patients' arthritis, researchers found blacks with the condition were half as likely to be on so-called biologic disease-modifying anti-rheumatic drugs (DMARDs), compared to the less-potent standard drugs.

"Biologics in (rheumatoid arthritis) are generally very potent and effective treatments to prevent disease progression but are quite expensive," Aniket Kawatkar, from Southern California Permanente Medical Group in Pasadena, told Reuters Health in an email.

Those drugs are typically delivered via subcutaneous injections, whereas standard DMARDs can be taken by mouth.

People with rheumatoid arthritis have worsening inflammation in the joints that leads to pain, stiffness and loss of function. According to the Arthritis Foundation, 1.3 million people in the United States have the disease. It is much less common than osteoarthritis, the common "wear-and-tear" type of joint disease.

Although rheumatoid arthritis isn't curable, anti-rheumatic drugs can keep joint damage and related symptoms from progressing.

Kawatkar, who worked on the new study, said there are a few reasons why blacks with rheumatoid arthritis might be less likely to be on more powerful drugs, even if their disease is just as severe.

"If patients do not have accesses to physician specialists who are better at management of (rheumatoid arthritis), this can affect the choice of DMARDs they are receiving," he said.

"Secondly, ethnic and cultural beliefs may hinder certain minorities from seeking care immediately."

Some drugs are generally considered to have a "window of opportunity" when they provide the most benefit.

"If cultural beliefs inhibit an (rheumatoid arthritis) patient for seeking care immediately, the window of opportunity for treatment may be lost," Kawatkar said.

RESULTS ‘UNSETTLING'

All 5,385 rheumatoid arthritis patients analyzed for the new study were on Medicaid, the government health program for the poor, so income wasn't a major difference between patient groups. The patients - in their 50s and 60s, on average - were treated with at least one anti-rheumatic drug in California between 1998 and 2005.

Overall, 16 percent of white patients took biologic DMARDs, which include etanercept (marketed as Enbrel) and adalimumab (Humira). The rest took standard DMARDs, such as methotrexate (Rheumatrex) and leflunomide (Arava).

In comparison, about nine percent of black patients took the more potent drugs.

Hispanic rheumatoid arthritis patients were most likely to be on biologic DMARDs: 20 percent of them took those medications during the study period. They also tended to have more severe joint pain and activity limitations than whites.

Dr. Kenneth Saag, an immunologist from the University of Alabama at Birmingham, called the findings "unsettling."

He said black people with rheumatoid arthritis may know fewer members of their community who are on biologic DMARDs, and so aren't as comfortable trying them. Or, doctors could have misconceptions about arthritis not being as severe in certain types of patients.

"Regrettably, there may be elements of discrimination in terms of what therapies are offered to people," Saag, who wasn't involved in the new study, told Reuters Health.

He said that in some practices, as many as 60 percent of rheumatoid arthritis patients are taking the more potent drugs.

The researchers wrote in the journal Arthritis Care & Research that there's no consensus opinion on which drugs are best for which rheumatoid arthritis patients.

"This determination should always be made by the rheumatologist based on their assessment of the patient's condition," Kawatkar said.

"In general though, these drugs are given to patients who have active and aggressive (forms) of the disease and/or patients who are more likely to progressive to a more severe stage relatively quickly."

Standard DMARDs typically cost a few hundred dollars per year, he said - while biologic drugs can cost between $15,000 and $25,000. Such drugs are typically covered by Medicaid with prior approval.

SOURCE: bit.ly/O2gAHJ Arthritis Care & Research, online July 17, 2012.

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