Drugs May Increase Shingles Risk

By Robert H. Shmerling, M.D.
Content provided by the Faculty of the Harvard Medical School

Some drugs used to treat autoimmune diseases may increase the risk of a painful skin infection, a study finds. The study focused on people who take TNF blockers. These drugs suppress the immune system. They can help people with rheumatoid arthritis and some other diseases caused by the immune system attacking the body. The study tracked 5,040 people with rheumatoid arthritis. In a 3-year period, 82 developed shingles. This is a skin disease caused by the varicella-zoster virus. People were twice as likely to develop shingles if they took infliximab (Remicade) or adalimumab (Humira). Both drugs are TNF blockers. The study appeared in the Journal of the American Medical Association. HealthDay News wrote about it February 17.

What Is the Doctor's Reaction?

Shingles is a common infection, also known as herpes zoster. Shingles causes a painful rash. It affects up to 500,000 people each year in the United States.

The way it develops is unusual.

Chickenpox and shingles are caused by the same virus. Chickenpox usually occurs during childhood. Then the virus can stay in the body but cause no problems for years (and often decades). If it gets active again, it causes a rash over a patch of skin. The rash may be painful or feel like it's burning. This is called shingles.

People who are sick or have a suppressed immune system may be more likely to get shingles. Often it re-emerges for no apparent reason.

A new study finds that people who take one class of drugs are more likely to get shingles. The drugs are called anti-TNF antibodies. They include adalimumab (Humira) and infliximab (Remicade). These drugs are taken most commonly to treat rheumatoid arthritis. However, they are also used to treat other types of arthritis, psoriasis and Crohn's disease.

TNF stands for tumor necrosis factor. It plays a key role in the long-term inflammation that is part of these conditions.

A third anti-TNF drug, etanercept (Enbrel), is not an antibody to TNF. It works in a different way, by grabbing onto TNF and preventing it from causing inflammation and tissue damage. This new study did not find a link between etanercept and shingles. In addition, this study did not analyze the risk of shingles for the newest anti-TNF drugs, certolizumab (Cimzia) and golimumab (Simponi).

It's not surprising that treatment with certain anti-TNF drugs might increase the risk of shingles. People with rheumatoid arthritis are already at increased risk for shingles. And anti-TNF treatment suppresses the immune system. This clearly increases the risk of shingles.

Research trials of anti-TNF drugs already noted that herpes zoster infections were among the most common side effects. To me, the only surprising finding of this research was that etanercept did not lead to an increased risk of shingles as the other anti-TNF drugs did.

These findings should allow patients considering treatment with anti-TNF drugs to better understand the risks they face. And this study should encourage doctors to suspect shingles in patients who have certain symptoms. That's important because early diagnosis may alter the choice of treatment for shingles.

For example, taking anti-viral drugs (such as acyclovir/Zovirax) within the first three days of symptoms may shorten the illness. Treatment also may reduce the risk of post-herpetic neuralgia. This painful nerve condition may develop after a case of shingles. This study also should encourage efforts to prevent shingles in people who will be taking anti-TNF drugs.

What Changes Can I Make Now?

Talk to your doctor about vaccination for shingles. Current guidelines suggest that it be routinely considered for all people over the age of 60.

If you are considering taking anti-TNF treatment, be sure you know its potential risks and benefits. On the benefit side, these medicines can dramatically reduce the activity of the disease. For people with arthritis, these medicines can quickly stop joint damage from getting worse.

This new research also listed other common risks of anti-TNF therapy. They include:

  • Injection site reactions -- Redness or itching, for example, may temporarily develop at the site where the shot was given.

  • Tuberculosis (TB) -- Most cases occur among people exposed to TB in the past.

  • Other infections -- These may caused by bacteria, viruses or fungi.

  • Rash

  • Nausea

  • Allergic reactions, such as rash or facial swelling

Take steps to reduce these risks. For example:

  • Have a skin test for tuberculosis before you start anti-TNF therapy.

  • If your skin test or chest X-ray shows signs of prior TB exposure, take antibiotics before you start anti-TNF drugs. (If you have evidence of active infection, avoid anti-TNF treatment.)

  • Let your doctor know if you have a fever, cough or other unexplained symptoms. In general, anti-TNF drugs should be stopped if you have a major infection, especially one that causes a fever or requires antibiotics.

  • Ask your doctor whether you should get a shingles vaccine before starting anti-TNF treatment. The vaccine contains live virus. It should not be given to people already taking anti-TNF medicines.

What Can I Expect Looking to the Future?

Anti-TNF drugs are very effective. They have an outstanding safety record. Therefore, they probably will be used to treat a growing number of conditions. You can expect to hear more about studies that assess the safety of these drugs. The studies could lead to new guidelines regarding their use. Based on this new study, experts may recommend routine shingles vaccination before people start anti-TNF treatment.

Last Annual Review Date: 2009-02-18T00:00:00-07:00

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