RA Drugs May Boost Infection Risk

Rheumatoid arthritis patients face serious infection risk within first year of continuous TNF inhibitor use

/ Author:  / Reviewed by: Robert Carlson, M.D

(RxWiki News) Rheumatoid arthritis patients are commonly treated with anti-TNF medications. As with many arthritis drugs, there are concerns that anti-TNF drugs may lead to some serious side effects.

Continuous treatment with anti-TNF drugs may increase the risk of serious infections in people with rheumatoid arthritis within the first year of treatment.

After the first year of treatment, however, the risk of serious infection was not as high.

"Ask your doctor about the risks of your arthritis drugs."

Tumor necrosis factor (TNF) is a chemical made by the immune system that can lead to inflammation, a key characteristic of rheumatoid arthritis. Anti-TNF drugs block this chemical and reduce inflammation.

Dr. Masayoshi Harigai, of Tokyo Medical and Dental University, and colleagues set out to study the relationship between continuous treatment with anti-TNF drugs and the risk of developing serious infections among people with rheumatoid arthritis.

Patients were followed for 3 years.

Overall, rheumatoid arthritis patients taking anti-TNF drugs were nearly twice as likely, than those who did not take anti-TNF drugs, to develop serious infection.

Within the first year of treatment, patients taking anti-TNF drugs were 2.4 times more likely to develop serious infections, compared to those who did not take anti-TNF drugs.

The risk of serious infection dropped for the second and third years of treatment. Patients taking anti-TNF drugs were 1.38 times more likely to develop serious infection in the second and third year of treatment, compared to those who did not take anti-TNF drugs.

In their study, the researchers compared the risk of serious infection in two anti-TNF drugs: Enbrel (etanercept) and Remicade (infliximab).

Patients taking etanercept did not have a significantly higher risk of infection compared to those taking infliximab.

According to the study's authors, "Continuous anti-TNF therapy was significantly associated with increased risks for developing serious infections during, but not after, the first year."

For their research, Dr. Harigai and colleagues studied 727 rheumatoid arthritis patients who had started taking either etanercept or infliximab and 571 patients who had started taking nonbiologic disease-modifying antirheumatic drugs (DMARDs).

The authors reported receiving income from a variety of pharmaceutical companies, including Abbott, Mitsubishi Tanabe, Eisai, Pfizer, Takeda, AstraZeneca, GlaxoSmithKline and Bristol-Myers Squibb among others.

The study was funded by the Japanese Ministry of Education, Abbott Laboratores, Bristol-Myers Squibb, Eisai, Chugai Pharmaceutical, Mitsubishi Pharmaceutical, Takeda Pharmaceutical, Pfizer Japan and other sources.

The research was published July 27 in Arthritis Care & Research.

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Review Date: 
August 8, 2012
Last Updated:
August 11, 2012