The Food and Drug Administration approved Thursday revised warnings for several anemia drugs used in kidney-failure and chemotherapy patients.

Amgen and Johnson & Johnson strengthened the label warnings for three widely used anemia drugs Thursday, cautioning that risks, including stroke, worsening of cancer and death, are associated with their use, even in doses previously considered safe.

The products are Amgen's Epogen and Aranesp and Johnson & Johnson's Procrit, used to treat blood disorder anemia in kidney-failure and chemotherapy patients. They are commonly referred to as ESAs.

The revisions expand milder labeling changes made in March 2007, reports WebMD, and refer to risks for certain cancer patients and patients with chronic kidney failure. The revised boxed warning label also includes a statement that these anemia drugs have not been shown to improve symptoms of anemia, fatigue, and quality of life in cancer patients.

The new labeling warns cancer patients undergoing chemotherapy that the drugs caused tumor growth and decreased survival in patients with advanced breast, head and neck, lymphoid and non-small cell lung cancer, reports the Associated Press.

At the FDA's request, the companies also strengthened a warning that using the drugs in higher doses can increase risk of heart attack, stroke, and death in kidney failure patients. The label cautions physicians that using higher-than-recommended doses of the drugs does not benefit patients. FDA emphasized that it is still unclear whether cancer patients face the same risks even when using normal doses of the drugs.

The FDA warning on the agency’s website reads: “This information reflects FDA’s preliminary analysis of data concerning this drug. FDA is considering, but has not reached a final conclusion about, this information. FDA intends to update this sheet when additional information or analyses become available.”

Approximately one million Americans use the drugs each year, most of these being patients with cancer chemotherapy or kidney failure that develop anemia. Combined sales worldwide were nearly $10 billion last year.

FDA warning: http://www.fda.gov/cder/drug/infopage/RHE/default.htm