Tuberculosis Linked to Arthritis Drugs
Doctors Should Screen for TB Before Prescribing Drugs That Suppress Immune System
Aug. 5, 2004 -- Several cases of tuberculosis (TB) have been linked to drugs commonly prescribed for arthritis, the CDC reports.
Doctors who prescribe potent immune-suppressing drugs for their rheumatoid arthritis patients should screen them for TB exposure and infection before prescribing these drugs, the CDC says. Tuberculosis is common in certain settings like jails, prisons, homeless shelters, chronic-care facilities, and in some countries.
The arthritis drugs are all in a class called tumor necrosis factor-alpha (TNF-a) antagonist drugs and include Remicade, Enbrel, and Humira. These drugs work by blocking TNF-a, a chemical that triggers inflammation. They are approved for treating rheumatoid arthritis and other autoimmune diseases where inflammation is a key component of the illness.
This same inflammatory chemical -- TNF-a -- is also associated with certain infectious diseases like tuberculosis. Blocking this chemical can allow a latent TB infection to emerge, says the CDC report.
Tuberculosis is caused by bacteria that mainly attack the lungs. Often the body can fight a TB infection, but the bacteria remain dormant in the body.
TNF-a blocker medications suppress the immune system and can allow the bacteria to re-emerge and cause tuberculosis. This is called a latent infection.
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In 2002, three cases of tuberculosis occurred in people taking Remicade. Nine more cases have been reported in California. According to the CDC's report, most of the reported cases are latent infections.
Details on the infected people:
The average age is 55, and 67% are female.
Fever, cough, weight loss, and enlarged lymph nodes are initial symptoms.
Eleven developed tuberculosis after receiving Remicade.
Eleven of the patients had been in countries where tuberculosis is common or had contact with someone infected with tuberculosis.
Eight were taking other medications that suppressed the immune system.
A few of the case studies:
A U.S.-born, 55-year-old man with rheumatoid arthritis was diagnosed with tuberculosis within 17 months of starting Remicade. Although his arthritis had improved, he developed fever, lost weight, and developed an enlarged lymph node. He then had a chest X-ray, which showed evidence of TB. He was treated with medications but has since died of lung cancer (he was a longtime smoker).