FDA-Approved Arthritis Drugs Could Lead to Fatal Fungal Infections

September 05, 2008 03:09 PM
by Cara McDonough
The four arthritis drugs are the latest approved medications to necessitate stronger warnings from the FDA, after reports of deaths have surfaced.

A Serious Complication

Enbrel, Remicade, Humira and Cimzia are drugs that provide relief from the swollen and painful joints associated with rheumatoid arthritis. The problem, however, is that the drugs work by suppressing the immune system to keep it from attacking the body, which means they make people more susceptible to various infections, the Associated Press reports.

Dr. Jeffrey Siegel of the U.S. Food and Drug Administration said the agency recently became concerned when 240 cases of a fungal infection called histoplasmosis surfaced in people taking the arthritis drugs, resulting in 45 deaths.

The news comes on the heels of the announcement of an FDA investigation of a possible cancer link with the FDA-approved cholesterol-lowering drug Vytorin.

Histoplasmosis, which attacks the respiratory system but can spread to other organs leading to fatal consequences, has symptoms like the flu. So not only is it difficult to diagnose, but may be caught too late.

The FDA has issued a warning about histoplasmosis to healthcare professionals on its Web site, noting that the infection is not “consistently recognized” in patients taking the drugs.

Siegal said that the FDA warning means the risk of the fungal infection will be listed in a “black box,” which is “the strongest warning information in a drug's prescribing literature.”

Patients who take any of the four arthritis drugs and exhibit any signs of histoplasmosis, including persistent fever, cough, shortness of breath or fatigue, are urged to call their doctor.

Related Topic: Recent FDA warnings

The histoplasmosis finding is the latest in what seems to be a long list of FDA-issued drug warnings in recent months.

The agency is still working on the possible Vytorin–cancer link, and has not yet urged patients to stop taking the drug. Clinical trial results released in July showed that, in a study of more than 1,800 people, 93 people who took Vytorin developed cancer, compared with 65 in a control group. But two studies currently underway have shown no increased risk, according to the FDA.

Also in July, the FDA began researching whether moving away from traditional benchmarks, such as lowering blood sugar and bad cholesterol, is necessary in diabetes and cholesterol drugs. As it stands, drug companies only need to prove that a diabetes drug lowers blood sugar, for instance, but not that it actually saves lives.

In November 2007, the FDA investigated reports of increased depression and suicide related to the drug Chantix, prescribed to patients who want to quit smoking. While the drug’s manufacturer, Pfizer, has posted specific warnings on its Web site about the drug, Chantix is still distributed widely.

Analysis: The politics of drug approval

If so much can go wrong after drugs are approved by the FDA, how does the agency go about approving the drugs in the first place?

The financial Web site The Motley Fool offers a post on “The Anatomy of an Approved Drug,” focusing on some of the politics of FDA drug approval. For instance, “drugs subjected to an advisory-committee hearing fare worse than drugs for which the agency doesn’t hold a panel hearing,” according to the site.

Furthermore, past experience with the FDA as well as reputation help drug makers win faster approval. Fifty-one percent of drugs submitted for approval between 2002 and 2004 by manufacturers who had already received approval for other drugs got approved on the first try, whereas only 30 percent of drug makers without previous FDA approvals got their drugs approved.

Large, domestic pharmaceuticals have received special attention too, with a 64 percent approval rate between 2002 and 2004. Foreign pharmacies, on the other hand, received approvals at a rate of 43 percent.

Reference: Histoplasmosis


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