The US FDA has said that they are reviewing Amgen and Johnson & Johnson’s experimental blockbuster anemia drugs, which have been associated with higher death rates in a study involving stroke patients.

Earlier this month, a report by Johnson & Johnson, on results of a German trial showed increased death rate in stroke patients who were given the drug Eprex as compared to the placebo group. The study was conducted to see whether the drug, an unapproved use, could improve brain function in patients who had suffered stroke. Eprex’s been approved by the FDA for use in increasing red blood cell levels in people suffering from anemia, a blood disorder that causes fatigue.

Anemia is the most common blood disorder worldwide. It causes fatigue and sometimes concentration problems and many other medical conditions since it leads to lack of oxygen in the organs.

In the study 522 people, a majority of whom were not anemic according to the FDA, were given relatively high doses of the drug or the placebo for a three day period. 4 % of the group that were given the drug Eprex suffered bleeding in the brain as a cause of death while it was 1 % in the case of the placebo group. Three months later 16 % of those who received Eprex died while only 9 % of the placebo group died.  

The drug Eprex is sold in the United States under the name of Procrit, by Johnson & Johnson and Amgen Inc. sells generically known epoetin alfa Eprex under the name of Epogen. A spokeswoman for the Thousand Oaks, Calif.-based company Amgen said the company is not conducting any trials of Epogen in stroke patients.

Federal health regulators in a statement posted online said they would work with the drug manufacturers "to evaluate the risk and benefits associated with the investigational uses" of the drugs.

They noted that the dosage used in the German study were higher than those currently on the drugs labels. In the past two years to warn of risks of tumor growth and heart problems when the drugs are used at higher doses, the FDA has bolstered warning labels on the drugs numerous times. The agency said they were waiting for more data on the trial in the coming weeks and would base on that make its recommendations to doctors and patients.