Contaminant Found in Heparin

March 5, 2008 — -- Investigators have found a contaminant in the blood-thinning drug heparin, the Food and Drug Administration announced today.

Those trying to determine what has caused a recent spike in allergic reactions and deaths associated with the medication now say they have found contamination only in the product whose ingredients came from China.

The FDA stopped short of saying that the problem originated in China, however, because of the complexity of the drug's supply chain.

The contaminant found in the drug acts like heparin, the FDA said, so it would not show up on traditional tests. Samples that tested positive contained 5 percent to 20 percent of the contaminant. But FDA stressed Wednesday that there is not yet a direct link between the contaminant and the adverse events.

"We do not know how it was introduced or how it got into these products," said Janet Woodcock, acting director of the FDA's Center for Drug Evaluation and Research. "We still don't know whether this inadvertently got into the supply or whether it was actually added."

The announcement today is the latest development in a heparin scare that prompted both the FDA and heparin maker Baxter Healthcare Corporation to take action.

In late February, Baxter issued a massive heparin recall and FDA regulators traveled to China to inspect its plant. Most of the raw ingredients for Baxter heparin come from Chinese suppliers, who provide the ingredients to processing plants in both China and Wisconsin before the drug arrives at its manufacturer.

The Wisconsin plant also gets raw ingredients from U.S. suppliers, but testing to date has shown no contaminants linked to the U.S. suppliers.

Baxter executives said the drug maker concluded that the problem did not occur in its New Jersey plant, which puts together the final product.

"We've excluded a number of potential causes," said Peter Arduini, president of Baxter's medication delivery business. "The active pharmaceutical ingredient is now the primary focus of our investigation."