Chinese inspectors have visited the Baxter International plant in New Jersey where the final processing of tainted heparin took place. The Food & Drug Administration (FDA) has said that the heparin from that plant was contaminated with a counterfeit ingredient from China. But the Chinese insist there is no evidence that the hundreds of adverse reactions and scores of deaths seen in US patients administered heparin are linked to the fake ingredient, and claim the problems could have originated in the US.
The FDA has linked tainted heparin with 81 deaths in the US, and hundreds of adverse reactions. Baxter International recalled nearly all its heparin injections in the U.S. after some patients experienced extreme – and in some cases fatal – allergic reactions, including difficulty breathing, nausea, vomiting, excessive sweating, and rapidly falling blood pressure that was life threatening after being administered the products. In March, the FDA confirmed that it had found oversulfated chondroitin sulfate in samples of the active ingredient used in Baxter heparin. The FDA said the chondroitin sulfate was molecularly changed to mimic heparin’s blood-clotting properties. That ingredient was supplied to Baxter by Changzhou SPL, a Chinese plant partially owned by Wisconsin-based Scientific Protein Laboratories LLC. Last week, FDA Commissioner Andrew von Eschenbach said that while the FDA has no specific evidence that the chondroitin sulfate contamination was intentional, “the concern is that it had to be by design.”
But at a news conference earlier this week, a Chinese official disputed that the heparin problems occurred in that country. Jin Shaohong, deputy director-general of the China National Institute for the Control of Pharmaceutical and Biological Products, said that Chinese investigators tested batches of heparin used by patients who reported health problems, and only some contained chondroitin sulfate. He also said that heparin with the contaminant has been found in many nations, but that none has reported a similar spike in harmful reactions as in the United States. Shaohong also said Chinese officials are focusing on the whole product, and speculated that other contaminants, problems with the device used to inject the heparin, or health factors with the patients who used the drug could also be causing the reactions.
But the FDA countered, saying a cluster of adverse reactions to heparin has been reported in Germany. Evidence is also growing that implicates the chondroitin sulfate in the US reactions. Janet Woodcock, director of the FDA’s Center for Drug Evaluation and Research said that Chinese officials had tested batches of heparin with methods less sensitive than those used in the US and elsewhere and had missed the presence of the contaminant. She said FDA scientists now believe the adverse reactions were most pronounced when large doses of the drug were administered quickly, and the contaminant acted as a “mediator” that caused a response similar to an allergic reaction.
According to The New York Times, the FDA has identified 12 Chinese companies that have supplied contaminated heparin to 11 countries — Australia, Canada, China, Denmark, France, Germany, Italy, Japan, the Netherlands, New Zealand and the United States. The FDA has not determined the original source of all the contamination or the points in the supply chain at which it was added. The Times also said officials have discovered heparin lots that included the cheap fake additive manufactured as early as early as 2006, although a spike in illnesses associated with contaminated heparin began in November and persisted through February.
The Chinese inspectors finished their tour of Baxter’s plant yesterday. So far, neither the Chinese nor Baxter will comment on the inspection.