Experimental Blood Substitutes Unsafe, Study Finds

April 28 -- MONDAY, April 28 (HealthDay News) -- Experimental hemoglobin-based blood substitutes boost the odds of death and heart attack for recipients, according to an exhaustive review of the data.

These products are not yet approved for use in the United States but have undergone extensive clinical testing.

The study, released early Monday by the Journal of the American Medical Association, has critics charging that the U.S. Food and Drug Administration failed to detect and act on a significant increase in heart attacks and deaths noted in trials of these laboratory-made blood substitutes.

That delay put participants in ongoing trials in jeopardy, they said.

"What I would like to see come out of this is a change in the rules about how the FDA handles data from clinical trials," said study co-author Dr. Charles Natanson, head of the anesthesia section of the U.S. National Institutes of Health's Clinical Center in Bethesda, Md.

"They should not be treated as trade secrets. The results should be made public in a short period of time," he said.

The report looked at data from 16 trials of five experimental artificial blood products, involving 3,711 patients. The researchers found an overall 30 percent increased risk of death and nearly triple the risk of heart attack for persons who got these products compared to those who did not.

Yet five trials of such products are still ongoing in eight countries outside the United States, and the FDA is considering a request for a trial here, the report's authors said.

An artificial blood product -- one with a longer shelf life and without the need for refrigeration required for human blood -- is a long-sought therapeutic goal. All the products described in the report are based on hemoglobin, the oxygen-carrying protein found in red blood.

The problem with such products is that "these hemoglobins do not have the protection of red blood cells," said study co-author Dr. Sidney Wolfe, director of the health research group at Washington, D.C.-based Public Citizen, an advocacy group that is often at odds with government agencies.