Heparin contaminant identified

WASHINGTON -- U.S. health officials have identified a contaminant in batches of the blood thinner heparin associated with 19 deaths and are trying to determine how the chemical got into the drug.

The lots of heparin, whose key ingredient was imported from China, were recalled Feb. 28, and Food and Drug Administration officials said Wednesday no new deaths have been reported since that time.

Dr. Janet Woodcock, head of the FDA's Center for Drug Evaluation and Research, said the contaminant is oversulfated condroitin sulfate, a chemical that does not occur naturally.

Condroitin sulfate is a natural compound that occurs widely and is used as a dietary supplement but the oversulfated version has not been widely studied.

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

The FDA has also initiated testing of imported heparin entering this country, and Woodcock said the agency feels "doctors and patients now can be confident that the product on the market has been tested and is safe."

Condroitin sulfate is a compound in the same family as heparin, so preliminary testing did not identify it, Woodcock said. She said more exacting tests by the government and university researchers uncovered the contaminant.

Oversulfated condroitin sulfate would be less expensive to make than heparin, but FDA officials said they could not estimate the cost difference.

Congress quickly reacted to the report, and the House Committee on Energy and Commerce's subcommittee on oversight and investigations scheduled an April 15 hearing.

"This latest development underscores our concerns that FDA does not have a robust enough presence overseas in conducting inspections in plants that make drugs for the U.S. market. Ongoing surveillance inspections are critical if FDA is to find shortcomings," said committee chairman John Dingell, a Michigan Democrat.

The lots of heparin linked to hundreds of allergic reactions were marketed by Deerfield-based Baxter International and produced in China.

Baxter buys its heparin through Wisconsin-based Scientific Protein Laboratories, or SPL, which in turn owns a Chinese factory -- Changzhou SPL -- and buys additional raw heparin from other Chinese suppliers.

SPL said in a statement Wednesday the contamination occurred earlier in the supply chain.