Drug News
Heparin contaminant identified, but its role unknown
By Sue Mueller
Mar 19, 2008 - 11:20:52 AM

WEDNESDAY March 19, 2008 (Foodconsumer.org) -- Officials at the Food and Drug Administration said a contaminant in batches of the blood thinner heparin made by Baxter International has been identified and now investigators are trying to figure out how this contaminant got into the drug, The Associated Press reported today.

Baxter's heparin based on a key raw active ingredient imported from China has been associated with more than 700 allergic reactions and at least 19 deaths, prompting the manufacturer to recall all brands of its heparin on Feb 28.

The heparin ingredient is isolated from pigs' intestines.  In the case of Baxter heparin small workshops collect the material from slaughterhouses and sell it to middlemen or consolidators who in turn sell it to a manufacturer in Changzhou, a city near Shanghai.  The Changzhou plant is a joint venture partner of Wisconsin-based Scientific Protein Laboratories.

The contaminant has been identified by the agency scientists and University researchers as overfulfated chondroitin sulfate, which does not occur naturally, said Dr. Janet Woodcock, head of the FDA's Center for Drug Evaluation and Research.

Chondroitin sulfate is a supplement commonly used to help joint conditions in arthritis patients. But the oversulfated version has not been widely studied.  Chondroitin sulfate is in the same family as heparin, which makes it difficult to identify this contaminant.

"We cannot rule in or out whether this was accidentally or deliberately introduced into the product," Woodcock was quoted as saying, "We are investigating how it got in."

Even if the officials in the end find out how the contaminant got into the drug, the question remains, is this contaminant responsible for the allergic reactions and deaths?

FDA officials said they were not yet able to directly associate the oversulfated chondroitin sulfate to the deaths and allergic reactions although the contaminant is the only suspect they have found in the drug.

On another front, a different brand of heparin has also been recalled in Germany after the government found this drug was linked to illness in 80 patients.  The manufacturer said the source of the contamination may be another Chinese supplier.  

But German officials did not say whether the contaminant is oversulfated chondroitin sulfate.