Blood-Thinner Contaminant Traced to Chinese Plant
Friday, March 14, 2008; 12:00 AM
FRIDAY, March 14 (HealthDay News) -- The contaminant found in the blood-thinner heparin, which has been linked to hundreds of allergic reactions and possibly 19 deaths in the United States, has been traced to a Chinese plant that processed raw ingredients for the drug, U.S. health officials said Friday.
As a result, the U.S. Food and Drug Administration said it will start testing all heparin products to be imported into the United States. The announcement comes as the agency continues its investigation into the contamination with heparin produced by Baxter Healthcare Corp., of Deerfield, Ill.
The heparin was supplied to Baxter by Scientific Protein Laboratories of Waunakee, Wisc., and its Changzhou SPL plant in Changzhou City, China. The company is Baxter's main supplier of the active pharmaceutical ingredient in heparin.
"The active pharmaceutical ingredient comes from the Changzhou SPL plant in China," Dr. Janet Woodcock, director of the FDA's Center for Drug Evaluation and Research, said during an afternoon teleconference.
"The FDA conducted an inspection in this plant, and we obtained 28 samples of the active pharmaceutical ingredient," Woodcock said. "We found 20 of these samples had a heparin-like contaminant."
In light of the finding, the FDA has placed the Changzhou SPL plant on "import alert," Woodcock said, meaning the plant has agreed not to export any more heparin to the United States.
In a statement released late Friday, Baxter said its staffers "have been working seven days a week since late December 2007" trying to determine the nature of the contaminant. The company has so far ruled out a number of infectious pathogens, dioxins or the pufferfish toxin (tetrodoxin).
"While Baxter's analysis is not complete, the company has evidence that the unknown material is a highly sulfated glucosaminoglycan-like (GAG-like) material," the company said. "While heparin-like, the material is structurally different from naturally-occurring heparin. The unknown material has approximately the same molecular weight as heparin and is similar in other ways, which is why standard testing would not detect its presence."
In the meantime, all other heparin destined for the United States from abroad must be tested for the contaminant by the manufacturers of the drug, the FDA's Woodcock said. Five manufacturers have agreed to such testing. Any manufacturers that don't agree to test will have their products withheld by the FDA for testing by the agency, she said.
These five manufacturers that have agreed to the testing make up a "substantial" portion of the heparin supply in the United States, Woodcock said. "Manufacturers making this test commitment will be able to import the active product ingredient from overseas sources without delay to avoid shortages in supply of heparin, which would also be a very dangerous situation for patients," she said.
Heparin is a blood thinner often given to dialysis patients and people undergoing heart surgery. The raw materials for the drug come from the mucous lining of pig intestines. Many of those pigs come from rural farms in China, with the intestines often processed by unregulated mom-and-pop workshops before further processing at Scientific Protein's plant in Changzhou.
The FDA hadn't uncovered a direct link between the contaminant and the adverse reactions and deaths. "We know that some of the suspect batches of heparin that were causing the adverse events have this contaminant in it. So there is an association between the contaminant in the presence of adverse events, but it is not a direct causal link yet," Woodcock said at a March 5 press conference.