Medications given to treat anemia in kidney and cancer patients greatly increase the risk of cardiovascular problems and need to be used more conservatively, the Food and Drug Administration has said.

The medicines, known as Erythropoiesis-Stimulating Agents (ESA) are approved to treat anemia resulting from Chronic Kidney Disease, chemotherapy and other conditions. But clinical trials have showed an increased risk of heart attacks, thrombosis and strokes when the drugs are given at high enough levels to get a normal blood hemoglobin level. Additionally, ESAs also do not improve quality of life, fatigue or patient well-being, the FDA stated Friday.

“Healthcare practitioners should carefully consider when to begin treatment with an ESA and actively monitor dosing in patients with chronic kidney disease, keeping in mind the increased risk for serious cardiovascular events, and should talk to their patients about these potential risks,” said John Jenkins, M.D., director of the Office of New Drugs in the FDA’s Center for Drug Evaluation and Research. “The goal is to individualize therapy and use the lowest ESA dose possible to reduce the need for red blood cell transfusions.”

In addition to the side effects, critics charge that these medicines were the single biggest drug expense in the federal Medicare program, costing the federal government more than $60 billion since they debuted in 1989, The New York Times reported. “Sixty billion dollars have gone out the window on these drugs, and what do we have to show for it?” Dennis Cotter, president of Medical Technology and Practice Patterns, a nonprofit health policy research institute in Bethesda, MD, asked rhetorically in The Times.