Reversing Anemia Can Threaten Kidney Patients

FDA to review use of blood-boosting drugs after worrisome findings from two trials.

By Serena Gordon
HealthDay Reporter
Thursday, November 16, 2006; 12:00 AM

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THURSDAY, Nov. 16 (HealthDay News) -- For kidney disease patients, using drugs to reverse anemia by boosting red blood cell counts past U.S. Food and Drug Administration-recommended levels may do more harm than good, two new studies warn.

In fact, one of the studies in this week's issue of the New England Journal of Medicine was stopped prematurely by its safety panel after researchers reported more deaths and complications in the high-hemoglobin group and little likelihood that the treatment would provide any patient benefit.

The findings prompted the FDA on Wednesday to say it would review data from the study -- called the CHOIR trial -- and revisit the question of exactly how much anemia correction is too much.

The outcome of the two NEJM trials is also stirring debate as to whether doctors are over-prescribing blockbuster anti-anemia drugs such as Amgen's Epogen and Johnson and Johnson's Procrit.

"Treatment of anemia is important, but care needs to be taken in how aggressively anemia is treated," said the lead author of the CHOIR trial, Dr. Ajay Singh, clinical chief of the renal division and director of dialysis at Brigham and Women's Hospital in Boston, Mass. "The current evidence suggests that too high a hemoglobin level may be associated with some risk."

Anemia is a common complication of kidney disease, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). That's because normally functioning kidneys produce the hormone erythropoietin (EPO), which is essential to the production of red blood cells. Once kidney disease develops, the kidneys often can't produce enough EPO anymore. Without enough EPO, the body doesn't make enough red blood cells and anemia results.

Hemoglobin is a component of red blood cells and is responsible for carrying oxygen throughout the body. Normal hemoglobin levels are between 13 and 15 grams per deciliter. Without the right number of red blood cells and hemoglobin, the body's tissues don't get enough oxygen to function properly. Anemic people get tired more easily and may develop heart problems, according to the NIDDK.