Is Infection a Serious Side Effect of DMARDs and Biologic Drugs?

Syringe & Ampules of Injectable Drugs
Infection as side effect of DMARDs and Biologic Drugs. BanksPhotos / Getty Images

Question: Is Infection a Serious Side Effect of DMARDs and Biologic Drugs?

Some patients are prone to common and serious infections while being treated with DMARDs or biologic drugs -- or does it just seem that way?


Feel Like You're Sick All the Time?

I've heard arthritis patients complain that since they started treatment with DMARDs (disease-modifying antirheumatic drugs) or injectable biologic drugs, they are frequently sick with colds, the flu, or infections.

I've heard many complain that if someone in their household "catches a bug," it is passed on to them without fail.

Arthritis patients taking DMARDs or biologic drugs realize that those drugs are classified as immunosuppressants. From that fact, you can assume that the immune system is turned down and doesn't have its normal gusto to fight off colds and infection. But being immunosuppressed doesn't mean you have no immunity at all. It's a bit confusing and provokes the following questions:

  • Do patients taking DMARDs or biologics really get sick more easily?
  • What actions can patients take to prevent sickness?
  • Is there a significant risk of serious infection associated with biologics?

What a Doctor Has to Say About It

We asked rheumatologist Scott J. Zashin, MD for his input. Zashin said, "Infection is probably the most common and most serious side effect of the TNF blockers (Enbrel, Remicade, Humira), one class of biologic drugs.

Although, in some clinical studies that compared rheumatoid arthritis patients treated with a TNF blocker versus control groups (often being treated with methotrexate), there was no increased risk of infection."

Zashin continued, "In general, rheumatoid arthritis patients have a higher risk of infection compared to the general population due to a number of factors, such as concomitant medication use -- for example, taking a DMARD (methotrexate, Arava, Imuran) and a corticosteroid (prednisone).

Another risk includes disease activity. The more severe the disease, the higher the risk of infection. Note that patients who have more severe disease are more likely to be on biologics, DMARDS and prednisone."

"Despite these confounding variables, most doctors feel that the TNF blockers are more likely to cause serious infections when compared to rheumatoid arthritis patients who are not on these medications," concluded Zashin.

Advice About Common Infections

When asked about common infections, Zashin said, "It is not uncommon to find patients who develop upper and lower respiratory infections on biologics and DMARDs, and the patients no longer have a problem when these medications are stopped. It is recommended that patients taking biologics and medications, such as methotrexate, be immunized for pneumococcal pneumonia at the recommended intervals and receive a yearly influenza vaccination."

Amgen Emphasizes Serious Infection Risk for Enbrel

On March 17, 2008, Amgen/Wyeth (the makers of Enbrel, one of the TNF blockers) announced that they updated the prescribing information for Enbrel by adding a boxed warning relating to the risk of infections, including tuberculosis. This is similar to labeling for other medications in the TNF blocker class.

The prescribing information previously contained a bolded warning regarding the risk of infections and tuberculosis.

The new boxed warning includes additional information regarding screening and monitoring patients for tuberculosis, including patients who tested negative for latent tuberculosis infection (latent TB means a patient is infected, but there is no active disease). In addition, the boxed warning states that tuberculosis has been observed in patients receiving TNF-blocking agents, including Enbrel, and that tuberculosis may be due to reactivation of latent tuberculosis infection or new infection.

The boxed warning notes that data from clinical trials and preclinical studies suggest that the risk of reactivation of latent tuberculosis infection is lower with Enbrel than with TNF-blocking monoclonal antibodies (like Remicade).

It's very important to be aware that infection, both common and serious infection, is a potential risk factor of using DMARDs or biologic drugs. You, as the patient, should work at staying as healthy as possible by eating right, getting enough sleep, taking vitamins, and exercising. You should notify your doctor when you experience signs and symptoms related to infection (malaise, fever, cough, flu-like symptoms).

Also read: Why is there an increased risk of infection which occurs with the TNF blockers?


Amgen and Wyeth Announce Updates to U.S. Prescribing Information for Enbrel. Amgen. March 17, 2008.

Dr. Zashin is ​a clinical assistant professor at University of Texas Southwestern Medical School and an attending physician at Presbyterian Hospitals of Dallas and Plano. Dr. Zashin is the author of Arthritis Without Pain - The Miracle Of TNF Blockers. The book is useful for anyone on one of the biologic drugs or considering the biologic drugs.

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