September 5, 2008

Arthritis Drugs Raise Risk of Fatal Infections

The Food and Drug Administration warned yesterday that a handful of medications commonly prescribed to treat rheumatoid arthritis and other serious illnesses can raise the risk of fatal fungal infections.

The drugs are called Enbrel, Remicade, Humira and Cimzia. They treat arthritis by suppressing the immune system to keep it from attacking the body.

The treatment provides relief from swollen and painful joints, but it's "a double-edged sword," said the FDA's Dr. Jeffrey Siegel. That's because he says the drugs can also lower the body's defenses to various infections.

Siegel heads the office that oversees arthritis drugs, and he said the FDA recently became concerned about the risk of infection called histoplasmosis.

Forty-five patients have died, of the 240 total cases reported to the FDA.

The infection is known to mimic the flu and is more common in the Midwest.

The infection can have particularly grave consequences if it is not detected and spreads beyond the respiratory system to other organs of the body.

The initial investigation started with a single case of a woman taking one of the drugs who died of histoplasmosis. Upon further research into the case, doctors found that the woman had been sick with the fungal infection for a long time.

"This case led us to be concerned that there may be other situations in which physicians may not recognize histoplasmosis," said Siegel.

Siegel said the FDA's order announced Thursday means that the potential risk of histoplasmosis will be noted in a "black box," the strongest warning information in a drug's prescribing literature.

The four medications under scrutiny already have black box warnings about the risk of infections. However, the language changes from drug to drug.

The FDA is urging doctors to consider aggressive use of antifungal drugs in patients who develop such symptoms, as a precautionary measure.

Siegel said antifungal drugs can also have dangerous side effects, so the decision should be made with care. Doctors should also consider stopping treatment with the immune-suppressing drugs if patients develop infections.

The FDA is also investigating a possible link between the four medications and cancer in young patients.

Earlier this year, the FDA got 30 reports of cancers, mainly lymphomas, in patients who began taking the medications when they were 18 or younger.

The findings of that investigation are expected later this year.

Three of the drugs, Enbrel, Humira and Remicade, are top sellers, with revenues of over $1 billion every year. Cimzia is newer and less widely used.

Humira is sold by North Chicago, Ill.-based Abbott Laboratories Inc; Cimzia by Belgium-based UCB; Enbrel by Thousand Oaks, Calif.-based Amgen Inc. and Madison, N.J.-based Wyeth ; and Remicade by Horsham, Pa.-based Centocor, a unit of Johnson & Johnson, and Kenilworth, N.J.-based Schering-Plough Inc.


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